Printhead assembly for a print on demand digital camera system

ABSTRACT

A printhead assembly for a camera system that includes an ink reservoir assembly that is mountable on the chassis of the camera system and defines at least three ink reservoirs in which differently colored inks are received. The ink reservoir assembly defines an outlet. A guide assembly is positioned in the ink reservoir assembly to define three discrete ink paths that open at the outlet. A printhead integrated circuit is positioned in the outlet to span the printing path. The printhead integrated circuit defines three sets of inlet apertures, each set of inlet apertures being aligned with a respective ink path.

[0001] This is a Continuation application of U.S. Ser. No. 09/112,774 filed on Jul. 10, 1998

FIELD OF THE INVENTION

[0002] The present invention relates substantially to the concept of a disposable camera having instant printing capabilities and in particular, discloses a printhead assembly for a digital camera system.

BACKGROUND OF THE INVENTION

[0003] Recently, the concept of a “single use” disposable camera has become an increasingly popular consumer item. Disposable camera systems presently on the market normally include an internal film roll and a simplified gearing mechanism for traversing the film roll across an imaging system including a shutter and lensing system. The user, after utilizing a single film roll returns the camera system to a film development center for processing. The film roll is taken out of the camera system and processed and the prints returned to the user. The camera system can then be re-manufactured through the insertion of a new film roll into the camera system, the replacement of any worn or wearable parts and the re-packaging of the camera system in accordance with requirements. In this way, the concept of a single use “disposable” camera is provided to the consumer.

[0004] Recently, a camera system has been proposed by the present applicant which provides for a handheld camera device having an internal print head, image sensor and processing means such that images sense by the image sensing means, are processed by the processing means and adapted to be instantly printed out by the printing means on demand. The proposed camera system further discloses a system of internal “print rolls” carrying print media such as film on to which images are to be printed in addition to ink to supplying the printing means for the printing process. The print roll is further disclosed to be detachable and replaceable within the camera system.

[0005] Unfortunately, such a system is likely to only be constructed at a substantial cost and it would be desirable to provide for a more inexpensive form of instant camera system which maintains a substantial number of the quality aspects of the aforementioned arrangement.

[0006] It would be further advantageous to provide for the effective interconnection of the sub components of a camera system.

SUMMARY OF THE INVENTION

[0007] According to a first aspect of the invention, there is provided a printhead assembly for a camera system having a chassis and a platen assembly that is mountable on the chassis, the platen assembly being configured to support passage of a print medium along a printing path, the printhead assembly comprising

[0008] an ink reservoir assembly that is mountable on the chassis and defines at least three ink reservoirs in which differently colored inks are received, the ink reservoir assembly defining an outlet;

[0009] a guide assembly that is positioned in the ink reservoir assembly to define at least three discrete ink paths that open at the outlet; and

[0010] at least one printhead integrated circuit that is positioned in the outlet to span the printing path, the, or each, printhead integrated circuit defining at least three sets of inlet apertures, each set of inlet apertures being aligned with a respective ink path.

[0011] The ink reservoir assembly may define three ink reservoirs and the guide assembly may define three discrete ink paths.

[0012] Both the ink reservoir assembly and the guide assembly may be elongate to span the printing path. The ink reservoir assembly may include an elongate base member and an elongate cover member, the cover member having a roof wall, a pair of opposed side walls and a pair of spaced inner walls, the side walls and the inner walls depending from the roof wall and being generally parallel to each other and the base member having a floor and a pair of opposed end walls and defining an elongate opening in which the printhead integrated circuits are mounted, the guide assembly being interposed between lower ends of the inner walls and the floor.

[0013] The guide assembly may include a pair of guide walls that extend from respective lower ends of the inner walls inwardly towards the elongate opening to define the three distinct ink paths that terminate at respective sets of inlet apertures of the printhead integrated circuits.

[0014] The base member, the cover member and the guide assembly may be molded of a plastics material.

[0015] One of the end walls may define a number of air inlet openings that are treated to be hydrophobic to permit the ingress of air into the ink reservoirs as ink is fed from the ink reservoirs and to inhibit the egress of ink.

[0016] A sponge-like member may be positioned in each ink reservoir to store the ink while inhibiting agitation of ink during general use of the camera system.

[0017] The invention extends to a camera system that includes a printhead assembly as described above.

[0018] In accordance with a second aspect of the present invention, there is provided in a camera system comprising: an image sensor device for sensing an image; a processing means for processing the sensed image; a print media supply means for the supply of print media to a print head; a print head for printing the sensed image on the print media stored internally to the camera system; a portable power supply interconnected to the print head, the sensor and the processing means; and a guillotine mechanism located between the print media supply means and the print head and adapted to cut the print media into sheets of a predetermined size.

[0019] Further, preferably, the guillotine mechanism is detachable from the camera system. The guillotine mechanism can be attached to the print media supply means and is detachable from the camera system with the print media supply means. The guillotine mechanism can be mounted on a platen unit below the print head.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Notwithstanding any other forms which may fall within the scope of the present invention, preferred forms of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:

[0021]FIG. 1 illustrates a front perspective view of the assembled camera of the preferred embodiment;

[0022]FIG. 2 illustrates a rear perspective view, partly exploded, of the preferred embodiment;

[0023]FIG. 3 is a perspective view of the chassis of the preferred embodiment;

[0024]FIG. 4 is a perspective view of the chassis illustrating mounting of electric motors;

[0025]FIG. 5 is an exploded perspective of the ink supply mechanism of the preferred embodiment;

[0026]FIG. 6 is rear perspective of the assembled form of the ink supply mechanism of the preferred embodiment;

[0027]FIG. 7 is a front perspective view of the assembled form of the ink supply mechanism of the preferred embodiment;

[0028]FIG. 8 is an exploded perspective view of the platen unit of the preferred embodiment;

[0029]FIG. 9 is a perspective view of the assembled form of the platen unit;

[0030]FIG. 10 is also a perspective view of the assembled form of the platen unit;

[0031]FIG. 11 is an exploded perspective view of the printhead recapping mechanism of the preferred embodiment;

[0032]FIG. 12 is a close up exploded perspective of the recapping mechanism of the preferred embodiment;

[0033]FIG. 13 is an exploded perspective of the ink supply cartridge of the preferred embodiment;

[0034]FIG. 14 is a close up perspective, view partly in section, of the internal portions of the ink supply cartridge in an assembled form;

[0035]FIG. 15 is a schematic block diagram of one form of integrated circuit layer of the image capture and processing integrated circuit of the preferred embodiment;

[0036]FIG. 16 is an exploded view perspective illustrating the assembly process of the preferred embodiment;

[0037]FIG. 17 illustrates a front exploded perspective view of the assembly process of the preferred embodiment;

[0038]FIG. 18 illustrates a perspective view of the assembly process of the preferred embodiment;

[0039]FIG. 19 illustrates a perspective view of the assembly process of the preferred embodiment;

[0040]FIG. 20 is a perspective view illustrating the insertion of the platen unit in the preferred embodiment;

[0041]FIG. 21 illustrates the interconnection of the electrical components of the preferred embodiment;

[0042]FIG. 22 illustrates the process of assembling the preferred embodiment; and

[0043]FIG. 23 is a perspective view further illustrating the assembly process of the preferred embodiment.

DESCRIPTION OF PREFERRED AND OTHER EMBODIMENTS

[0044] Turning initially simultaneously to FIG. 1 and FIG. 2 there are illustrated perspective views of an assembled camera constructed in accordance with the preferred embodiment with FIG. 1 showing a front perspective view and FIG. 2 showing a rear perspective view. The camera 1 includes a paper or plastic film jacket 2 which can include simplified instructions 3 for the operation of the camera system 1. The camera system 1 includes a first “take” button 4 which is depressed to capture an image. The captured image is output via output slot 6. A further copy of the image can be obtained through depressing a second “printer copy” button 7 whilst an LED light 5 is illuminated. The camera system also provides the usual view finder 8 in addition to a CCD image capture/lensing system 9.

[0045] The camera system 1 provides for a standard number of output prints after which the camera system 1 ceases to function. A prints left indicator slot 10 is provided to indicate the number of remaining prints. A refund scheme at the point of purchase is assumed to be operational for the return of used camera systems for recycling.

[0046] Turning now to FIG. 3, the assembly of the camera system is based around an internal chassis 12 which can be a plastic injection molded part. A pair of paper pinch rollers 28, 29 utilized for decurling are snap fitted into corresponding frame holes eg. 26, 27.

[0047] As shown in FIG. 4, the chassis 12 includes a series of mutually opposed prongs eg. 13, 14 into which is snapped fitted a series of electric motors 16, 17. The electric motors 16, 17 can be entirely standard with the motor 16 being of a stepper motor type. The motor 16, 17 include cogs 19, 20 for driving a series of gear wheels. A first set of gear wheels is provided for controlling a paper cutter mechanism and a second set is provided for controlling print roll movement.

[0048] Turning next to FIGS. 5 to 7, there is illustrated an ink supply mechanism 40 utilized in the camera system. FIG. 5 illustrates a back exploded perspective view, FIG. 6 illustrates a back assembled view and FIG. 7 illustrates a front assembled view. The ink supply mechanism 40 is based around an ink supply cartridge 42 which contains printer ink and a print head mechanism for printing out pictures on demand. The ink supply cartridge 42 includes a side aluminium strip 43 which is provided as a shear strip to assist in cutting images from a paper roll.

[0049] A dial mechanism 44 is provided for indicating the number of “prints left”. The dial mechanism 44 is snap fitted through a corresponding mating portion 46 so as to be freely rotatable.

[0050] As shown in FIG. 6, the mechanism 40 includes a flexible PCB strip 47 which interconnects with the print head and provides for control of the print head. The interconnection between the Flex PCB strip and an image sensor and print head integrated circuit can be via Tape Automated Bonding (TAB) Strips 51, 58. A moulded aspherical lens and aperture shim 50 (FIG. 5) is also provided for imaging an image onto the surface of the image sensor integrated circuit normally located within cavity 53 and a light box module or hood 52 is provided for snap fitting over the cavity 53 so as to provide for proper light control. A series of decoupling capacitors eg. 34 can also be provided. Further a plug 45 (FIG. 7) is provided for re-plugging ink holes after refilling. A series of guide prongs eg. 55-57 are further provided for guiding the flexible PCB strip 47.

[0051] The ink supply mechanism 40 interacts with a platen unit 60 which guides print media under a printhead located in the ink supply mechanism. FIG. 8 shows an exploded view of the platen unit 60, while FIGS. 9 and 10 show assembled views of the platen unit. The platen unit 60 includes a first pinch roller 61 which is snap fitted to one side of a platen base 62. Attached to a second side of the platen base 62 is a cutting mechanism 63 which traverses the platen unit 60 by means of a rod 64 having a screw thread which is rotated by means of cogged wheel 65 which is also fitted to the platen base 62. The screw threaded rod 64 mounts a block 67 which includes a cutting wheel 68 fastened via a fastener 69. Also mounted to the block 67 is a counter actuator which includes a pawl 71. The pawl 71 acts to rotate the dial mechanism 44 of FIG. 6 upon the return traversal of the cutting wheel. As shown previously in FIG. 6, the dial mechanism 44 includes a cogged surface which interacts with pawl 71, thereby maintaining a count of the number of photographs by means of numbers embossed on the surface of dial mechanism 44. The cutting mechanism 63 is inserted into the platen base 62 by means of a snap fit via clips 74.

[0052] The platen unit 60 includes an internal recapping mechanism 80 for recapping the print head when not in use. The recapping mechanism 80 includes a sponge portion 81 and is operated via a solenoid coil so as to provide for recapping of the print head. In the preferred embodiment, there is provided an inexpensive form of printhead re-capping mechanism provided for incorporation into a handheld camera system so as to provide for printhead re-capping of an inkjet printhead.

[0053]FIG. 11 illustrates an exploded view of the recapping mechanism whilst FIG. 12 illustrates a close up of the end portion thereof. The re-capping mechanism 80 is structured around a solenoid including a 16 turn coil 75 which can comprise insulated wire. The coil 75 is turned around a first stationery solenoid arm 76 which is mounted on a bottom surface of the platen base 62 (FIG. 8) and includes a post portion 77 to magnify effectiveness of operation. The arm 76 can comprise a ferrous material.

[0054] A second moveable arm 78 of the solenoid actuator is also provided. The arm 78 is moveable and is also made of ferrous material. Mounted on the arm is a sponge portion surrounded by an elastomer strip 79. The elastomer strip 79 is of a generally arcuate cross-section and act as a leaf spring against the surface of the printhead ink supply cartridge 42 (FIG. 5) so as to provide for a seal against the surface of the printhead ink supply cartridge 42. In the quiescent position an elastomer spring unit 87, 88 acts to resiliently deform the elastomer seal 79 against the surface of the ink supply unit 42.

[0055] When it is desired to operate the printhead unit, upon the insertion of paper, the solenoid coil 75 is activated so as to cause the arm 78 to move down to be adjacent to the end plate 76. The arm 78 is held against end plate 76 while the printhead is printing by means of a small “keeper current” in coil 75. Simulation results indicate that the keeper current can be significantly less than the actuation current. Subsequently, after photo printing, the paper is guillotined by the cutting mechanism 63 of FIG. 8 acting against Aluminium Strip 43, and rewound so as to clear the area of the re-capping mechanism 80. Subsequently, the current is turned off and springs 87, 88 return the arm 78 so that the elastomer seal is again resting against the printhead ink supply cartridge.

[0056] It can be seen that the preferred embodiment provides for a simple and inexpensive means of re-capping a printhead through the utilisation of a solenoid type device having a long rectangular form. Further, the preferred embodiment utilises minimal power in that currents are only required whilst the device is operational and additionally, only a low keeper current is required whilst the printhead is printing.

[0057] Turning next to FIGS. 13 and 14, FIG. 13 illustrates an exploded perspective of the ink supply cartridge 42 whilst FIG. 14 illustrates a close up sectional view of a bottom of the ink supply cartridge with the printhead unit in place. The ink supply cartridge 42 is based around a pagewidth printhead 102 which comprises a long slither of silicon having a series of holes etched on the back surface for the supply of ink to a front surface of the silicon wafer for subsequent ejection via a micro electro mechanical system. The form of ejection can be many different forms such as those set out in the tables below.

[0058] Of course, many other inkjet technologies, as referred to the attached tables below, can also be utilised when constructing a printhead unit 102. The fundamental requirement of the ink supply cartridge 42 is the supply of ink to a series of colour channels etched through the back surface of the printhead 102. In the description of the preferred embodiment, it is assumed that a three colour printing process is to be utilised so as to provide full colour picture output. Hence, the print supply unit includes three ink supply reservoirs being a cyan reservoir 104, a magenta reservoir 105 and a yellow reservoir 106. Each of these reservoirs is required to store ink and includes a corresponding sponge type material 107-109 which assists in stabilising ink within the corresponding ink channel and inhibiting the ink from sloshing back and forth when the printhead is utilised in a handheld camera system. The reservoirs 104, 105, 106 are formed through the mating of first exterior plastic piece 110 and a second base piece 111.

[0059] At a first end 118 of the base piece 111 a series of air inlet 113-115 are provided. Each air inlet leads to a corresponding winding channel which is hydrophobically treated so as to act as an ink repellent and therefore repel any ink that may flow along the air inlet channel. The air inlet channel further takes a convoluted path assisting in resisting any ink flow out of the chambers 104-106. An adhesive tape portion 117 is provided for sealing the channels within end portion 118.

[0060] At the top end, there is included a series of refill holes (not shown) for refilling corresponding ink supply chambers 104, 105, 106. A plug 121 is provided for sealing the refill holes.

[0061] Turning now to FIG. 14, there is illustrated a close up perspective view, partly in section through the ink supply cartridge 42 of FIG. 13 when formed as a unit. The ink supply cartridge includes the three colour ink reservoirs 104, 105, 106 which supply ink to different portions of the back surface of printhead 102 which includes a series of apertures 128 defined therein for carriage of the ink to the front surface.

[0062] The ink supply cartridge 42 includes two guide walls 124, 125 which separate the various ink chambers and are tapered into an end portion abutting the surface of the printhead 102. The guide walls 124, 125 are further mechanically supported by block portions eg. 126 which are placed at regular intervals along the length of the ink supply unit. The block portions 126 leave space at portions close to the back of printhead 102 for the flow of ink around the back surface thereof.

[0063] The ink supply unit is preferably formed from a multi-part plastic injection mould and the mould pieces eg. 110, 111 (FIG. 13) snap together around the sponge pieces 107, 109. Subsequently, a syringe type device can be inserted in the ink refill holes and the ink reservoirs filled with ink with the air flowing out of the air outlets 113-115. Subsequently, the adhesive tape portion 117 and plug 121 are attached and the printhead tested for operation capabilities. Subsequently, the ink supply cartridge 42 can be readily removed for refilling by means of removing the ink supply cartridge, performing a washing cycle, and then utilising the holes for the insertion of a refill syringe filled with ink for refilling the ink chamber before returning the ink supply cartridge 42 to a camera.

[0064] Turning now to FIG. 15, there is shown an example layout of the Image Capture and Processing integrated circuit (ICP) 48.

[0065] The Image Capture and Processing integrated circuit 48 provides most

[0066] of the electronic functionality of the camera with the exception of the print head integrated circuit. The integrated circuit 48 is a highly integrated system. It combines CMOS image sensing, analog to digital conversion, digital image processing, DRAM storage, ROM, and miscellaneous control functions in a single integrated circuit.

[0067] The integrated circuit is estimated to be around 32 mm² using a

[0068] leading edge 0.18 micron CMOS/DRAM/APS process. The integrated circuit size and cost can scale somewhat with Moore's law, but is dominated by a CMOS active pixel sensor array 201, so scaling is limited as the sensor pixels approach the diffraction limit.

[0069] The ICP 48 includes CMOS logic, a CMOS image sensor, DRAM, and analog circuitry. A very small amount of flash memory or other non-volatile memory is also preferably included for protection against reverse engineering.

[0070] Alternatively, the ICP can readily be divided into two integrated circuits: one for the CMOS imaging array, and the other for the remaining circuitry. The cost of this two integrated circuit solution should not be significantly different than the single integrated circuit ICP, as the extra cost of packaging and bond-pad area is somewhat cancelled by the reduced total wafer area requiring the color filter fabrication steps.

[0071] The ICP preferably contains the following functions: Function 1.5 megapixel image sensor Analog Signal Processors Image sensor column decoders Image sensor row decoders Analogue to Digital Conversion (ADC) Column ADC's Auto exposure 12 Mbits of DRAM DRAM Address Generator Color interpolator Convolver Color ALU Halftone matrix ROM Digital halftoning Print head interface 8 bit CPU core Program ROM Flash memory Scratchpad SRAM Parallel interface (8 bit) Motor drive transistors (5) Clock PLL JTAG test interface Test circuits Busses Bond pads

[0072] The CPU, DRAM, Image sensor, ROM, Flash memory, Parallel interface, JTAG interface and ADC can be vendor supplied cores. The ICP is intended to run on 1.5V to minimize power consumption and allow convenient operation from two AA type battery cells.

[0073]FIG. 15 illustrates a layout of the ICP 48. The ICP 48 is dominated by the imaging array 201, which consumes around 80% of the integrated circuit area. The imaging array is a CMOS 4 transistor active pixel design with a resolution of 1,500×1,000. The array can be divided into the conventional configuration, with two green pixels, one red pixel, and one blue pixel in each pixel group. There are 750×500 pixel groups in the imaging array.

[0074] The latest advances in the field of image sensing and CMOS image sensing in particular can be found in the October, 1997 issue of IEEE Transactions on Electron Devices and, in particular, pages 1689 to 1968. Further, a specific implementation similar to that disclosed in the present application is disclosed in Wong et. al, “CMOS Active Pixel Image Sensors Fabricated Using a 1.8V, 0.25 μm CMOS Technology”, IEDM 1996, page 915

[0075] The imaging array uses a 4 transistor active pixel design of a standard configuration. To minimize integrated circuit area and therefore cost, the image sensor pixels should be as small as feasible with the technology available. With a four transistor cell, the typical pixel size scales as 20 times the lithographic feature size. This allows a minimum pixel area of around 3.6 μm×3.6 μm. However, the photosite must be substantially above the diffraction limit of the lens. It is also advantageous to have a square photosite, to maximize the margin over the diffraction limit in both horizontal and vertical directions. In this case, the photosite can be specified as 2.5 μm×2.5 μm. The photosite can be a photogate, pinned photodiode, charge modulation device, or other sensor.

[0076] The four transistors are packed as an ‘L’ shape, rather than a rectangular region, to allow both the pixel and the photosite to be square. This reduces the transistor packing density slightly, increasing pixel size. However, the advantage in avoiding the diffraction limit is greater than the small decrease in packing density.

[0077] The transistors also have a gate length which is longer than the minimum for the process technology. These have been increased from a drawn length of 0.18 micron to a drawn length of 0.36 micron. This is to improve the transistor matching by making the variations in gate length represent a smaller proportion of the total gate length.

[0078] The extra gate length, and the ‘L’ shaped packing, mean that the transistors use more area than the minimum for the technology. Normally, around 8 μm² would be required for rectangular packing. Preferably, 9.75 μm² has been allowed for the transistors.

[0079] The total area for each pixel is 16 μm², resulting from a pixel size of 4 μm×4 μm. With a resolution of 1,500×1,000, the area of the imaging array 101 is 6,000 μm×4,000 μm, or 24 mm².

[0080] The presence of a color image sensor on the integrated circuit affects the process required in two major ways:

[0081] The CMOS fabrication process should be optimized to minimize dark current

[0082] Color filters are required. These can be fabricated using dyed photosensitive polyimides, resulting in an added process complexity of three spin coatings, three photolithographic steps, three development steps, and three hardbakes.

[0083] There are 15,000 analog signal processors (ASPs) 205, one for each of the columns of the sensor. The ASPs amplify the signal, provide a dark current reference, sample and hold the signal, and suppress the fixed pattern noise (FPN).

[0084] There are 375 analog to digital converters 206, one for each four columns of the sensor array. These may be delta-sigma or successive approximation type ADC's. A row of low column ADC's are used to reduce the conversion speed required, and the amount of analog signal degradation incurred before the signal is converted to digital. This also eliminates the hot spot (affecting local dark current) and the substrate coupled noise that would occur if a single high speed ADC was used. Each ADC also has two four bit DAC's which trim the offset and scale of the ADC to further reduce FPN variations between columns. These DAC's are controlled by data stored in flash memory during integrated circuit testing.

[0085] The column select logic 204 is a 1:1500 decoder which enables the appropriate digital output of the ADCs onto the output bus. As each ADC is shared by four columns, the least significant two bits of the row select control 4 input analog multiplexors.

[0086] A row decoder 207 is a 1:1000 decoder which enables the appropriate row of the active pixel sensor array. This selects which of the 1000 rows of the imaging array is connected to analog signal processors. As the rows are always accessed in sequence, the row select logic can be implemented as a shift register.

[0087] An auto exposure system 208 adjusts the reference voltage of the ADC 205 in response to the maximum intensity sensed during the previous frame period. Data from the green pixels is passed through a digital peak detector. The peak value of the image frame period before capture (the reference frame) is provided to a digital to analogue converter (DAC), which generates the global reference voltage for the column ADCs. The peak detector is reset at the beginning of the reference frame. The minimum and maximum values of the three RGB color components are also collected for color correction.

[0088] The second largest section of the integrated circuit is consumed by a DRAM 210 used to hold the image. To store the 1,500×1,000 image from the sensor without compression, 1.5 Mbytes of DRAM 210 are required. This equals 12 Mbits, or slightly less than 5% of a 256 Mbit DRAM. The DRAM technology assumed is of the 256 Mbit generation implemented using 0.18 μm CMOS.

[0089] Using a standard 8F cell, the area taken by the memory array is 3.11 mm². When row decoders, column sensors, redundancy, and other factors are taken into account, the DRAM requires around 4 mm².

[0090] This DRAM 210 can be mostly eliminated if analog storage of the image signal can be accurately maintained in the CMOS imaging array for the two seconds required to print the photo. However, digital storage of the image is preferable as it is maintained without degradation, is insensitive to noise, and allows copies of the photo to be printed considerably later.

[0091] A DRAM address generator 211 provides the write and read addresses to the DRAM 210. Under normal operation, the write address is determined by the order of the data read from the CMOS image sensor 201. This will typically be a simple raster format. However, the data can be read from the sensor 201 in any order, if matching write addresses to the DRAM are generated. The read order from the DRAM 210 will normally simply match the requirements of a color interpolator and the print head. As the cyan, magenta, and yellow rows of the print head are necessarily offset by a few pixels to allow space for nozzle actuators, the colors are not read from the DRAM simultaneously. However, there is plenty of time to read all of the data from the DRAM many times during the printing process. This capability is used to eliminate the need for FIFOs in the print head interface, thereby saving integrated circuit area. All three RGB image components can be read from the DRAM each time color data is required. This allows a color space converter to provide a more sophisticated conversion than a simple linear RGB to CMY conversion.

[0092] Also, to allow two dimensional filtering of the image data without requiring line buffers, data is re-read from the DRAM array.

[0093] The address generator may also implement image effects in certain models of camera. For example, passport photos are generated by a manipulation of the read addresses to the DRAM. Also, image framing effects (where the central image is reduced), image warps, and kaleidoscopic effects can all be generated by manipulating the read addresses of the DRAM.

[0094] While the address generator 211 may be implemented with substantial complexity if effects are built into the standard integrated circuit, the integrated circuit area required for the address generator is small, as it consists only of address counters and a moderate amount of random logic.

[0095] A color interpolator 214 converts the interleaved pattern of red, 2× green, and blue pixels into RGB pixels. It consists of three 8 bit adders and associated registers. The divisions are by either 2 (for green) or 4 (for red and blue) so they can be implemented as fixed shifts in the output connections of the adders.

[0096] A convolver 215 is provided as a sharpening filter which applies a small convolution kernel (5×5) to the red, green, and blue planes of the image. The convolution kernel for the green plane is different from that of the red and blue planes, as green has twice as many samples. The sharpening filter has five functions:

[0097] To improve the color interpolation from the linear interpolation provided by the color interpolator, to a close approximation of a sinc interpolation.

[0098] To compensate for the image ‘softening’ which occurs during digitization.

[0099] To adjust the image sharpness to match average consumer preferences, which are typically for the image to be slightly sharper than reality. As the single use camera is intended as a consumer product, and not a professional photographic products, the processing can match the most popular settings, rather than the most accurate.

[0100] To suppress the sharpening of high frequency (individual pixel) noise. The function is similar to the ‘unsharp mask’ process.

[0101] To antialias Image Warping.

[0102] These functions are all combined into a single convolution matrix. As the pixel rate is low (less than 1 Mpixel per second) the total number of multiplies required for the three color channels is 56 million multiplies per second. This can be provided by a single multiplier. Fifty bytes of coefficient ROM are also required.

[0103] A color ALU 113 combines the functions of color compensation and color space conversion into the one matrix multiplication, which is applied to every pixel of the frame. As with sharpening, the color correction should match the most popular settings, rather than the most accurate.

[0104] A color compensation circuit of the color ALU provides compensation for the lighting of the photo. The vast majority of photographs are substantially improved by a simple color compensation, which independently normalizes the contrast and brightness of the three color components.

[0105] A color look-up table (CLUT) 212 is provided for each color component. These are three separate 256×8 SRAMs, requiring a total of 6,144 bits. The CLUTs are used as part of the color correction process. They are also used for color special effects, such as stochastically selected “wild color” effects.

[0106] A color space conversion system of the color ALU converts from the RGB color space of the image sensor to the CMY color space of the printer. The simplest conversion is a 1's complement of the RGB data. However, this simple conversion assumes perfect linearity of both color spaces, and perfect dye spectra for both the color filters of the image sensor, and the ink dyes. At the other extreme is a tri-linear interpolation of a sampled three dimensional arbitrary transform table. This can effectively match any non-linearity or differences in either color space. Such a system is usually necessary to obtain good color space conversion when the print engine is a color electrophotographic

[0107] However, since the non-linearity of a halftoned ink jet output is very small, a simpler system can be used. A simple matrix multiply can provide excellent results. This requires nine multiplies and six additions per contone pixel. However, since the contone pixel rate is low (less than 1 Mpixel/sec) these operations can share a single multiplier and adder. The multiplier and adder are used in a color ALU which is shared with the color compensation function.

[0108] Digital halftoning can be performed as a dispersed dot ordered dither using a stochastic optimized dither cell. A halftone matrix ROM 216 is provided for storing dither cell coefficients. A dither cell size of 32×32 is adequate to ensure that the cell repeat cycle is not visible. The three colors—cyan, magenta, and yellow—are all dithered using the same cell, to ensure maximum co-positioning of the ink dots. This minimizes ‘muddying’ of the mid-tones which results from bleed of dyes from one dot to adjacent dots while still wet. The total ROM size required is 1 KByte, as the one ROM is shared by the halftoning units for each of the three colors.

[0109] The digital halftoning used is dispersed dot ordered dither with stochastic optimized dither matrix. While dithering does not produce an image quite as ‘sharp’ as error diffusion, it does produce a more accurate image with fewer artifacts. The image sharpening produced by error diffusion is artificial, and less controllable and accurate than ‘unsharp mask’ filtering performed in the contone domain. The high print resolution (1,600 dpi×1,600 dpi) results in excellent quality when using a well formed stochastic dither matrix.

[0110] Digital halftoning is performed by a digital halftoning unit 217 using a simple comparison between the contone information from the DRAM 210 and the contents of the dither matrix 216. During the halftone process, the resolution of the image is changed from the 250 dpi of the captured contone image to the 1,600 dpi of the printed image. Each contone pixel is converted to an average of 40.96 halftone dots.

[0111] The ICP incorporates a 16 bit microcontroller CPU core 219 to run the miscellaneous camera functions, such as reading the buttons, controlling the motor and solenoids, setting up the hardware, and authenticating the refill station. The processing power required by the CPU is very modest, and a wide variety of processor cores can be used. As the entire CPU program is run from a small ROM 220[.], program compatibility between camera versions is not important, as no external programs are run. A 2 Mbit (256 Kbyte) program and data ROM 220 is included on integrated circuit. Most of this ROM space is allocated to data for outline graphics and fonts for specialty cameras. The program requirements are minor. The single most complex task is the encrypted authentication of the refill station. The ROM requires a single transistor per bit.

[0112] A Flash memory 221 may be used to store a 128 bit authentication code. This provides higher security than storage of the authentication code in ROM, as reverse engineering can be made essentially impossible. The Flash memory is completely covered by third level metal, making the data impossible to extract using scanning probe microscopes or electron beams. The authentication code is stored in the integrated circuit when manufactured. At least two other Flash bits are required for the authentication process: a bit which locks out reprogramming of the authentication code, and a bit which indicates that the camera has been refilled by an authenticated refill station. The flash memory can also be used to store FPN correction data for the imaging array. Additionally, a phase locked loop resealing parameter is stored for scaling the clocking cycle to an appropriate correct time. The clock frequency does not require crystal accuracy since no date functions are provided. To eliminate the cost of a crystal, an on integrated circuit oscillator with a phase locked loop 224 is used. As the frequency of an on-integrated circuit oscillator is highly variable from integrated circuit to integrated circuit, the frequency ratio of the oscillator to the PLL is digitally trimmed during initial testing. The value is stored in Flash memory 221. This allows the clock PLL to control the ink-jet heater pulse width with sufficient accuracy.

[0113] A scratchpad SRAM is a small static RAM 222 with a 6T cell. The scratchpad provided temporary memory for the 16 bit CPU. 1024 bytes is adequate.

[0114] A print head interface 223 formats the data correctly for the print head. The print head interface also provides all of the timing signals required by the print head. These timing signals may vary depending upon temperature, the number of dots printed simultaneously, the print medium in the print roll, and the dye density of the ink in the print roll.

[0115] The following is a table of external connections to the print head interface: Connection Function Pins DataBits[0-7] Independent serial data to the eight segments of the print 8 head BitClock Main data clock for the print head 1 ColorEnable[0-2] Independent enable signals for the CMY actuators, 3 allowing different pulse times for each color. BankEnable[0-1] Allows either simultaneous or interleaved actuation of two 2 banks of nozzles. This allows two different print speed/power consumption tradeoffs NozzleSelect[0-4] Selects one of 32 banks of nozzles for simultaneous 5 actuation ParallelXferClock Loads the parallel transfer register with the data from the 1 shift registers Total 20 

[0116] The print head utilized is composed of eight identical segments, each 1.25 cm long. There is no connection between the segments on the print head integrated circuit. Any connections required are made in the external TAB bonding film, which is double sided. The division into eight identical segments is to simplify lithography using wafer steppers. The segment width of 1.25 cm fits easily into a stepper field. As the print head integrated circuit is long and narrow (10 cm×0.3 mm), the stepper field contains a single segment of 32 print head integrated circuits. The stepper field is therefore 1.25 cm×1.6 cm. An average of four complete print heads are patterned in each wafer step.

[0117] A single BitClock output line connects to all 8 segments on the print head. The 8 DataBits lines lead one to each segment, and are clocked into the 8 segments on the print head simultaneously (on a BitClock pulse). For example, dot 0 is transferred to segment₀, dot 750 is transferred to segment₁, dot 1500 to segment₂ etc simultaneously.

[0118] The ParallelXferClock is connected to each of the 8 segments on the print head, so that on a single pulse, all segments transfer their bits at the same time.

[0119] The NozzleSelect, BankEnable and ColorEnable lines are connected to each of the 8 segments, allowing the print head interface to independently control the duration of the cyan, magenta, and yellow nozzle energizing pulses. Registers in the Print Head Interface allow the accurate specification of the pulse duration between 0 and 6 ms, with a typical duration of 2 ms to 3 ms.

[0120] A parallel interface 125 connects the ICP to individual static electrical signals. The CPU is able to control each of these connections as memory mapped I/O via a low speed bus.

[0121] The following is a table of connections to the parallel interface: Connection Direction Pins Paper transport stepper motor Output 4 Capping solenoid Output 1 Copy LED Output 1 Photo button Input 1 Copy button Input 1 Total 8

[0122] Seven high current drive transistors eg. 227 are required. Four are for the four phases of the main stepper motors two are for the guillotine motor, and the remaining transistor is to drive the capping solenoid. These transistors are allocated 20,000 square microns (600,000 F) each. As the transistors are driving highly inductive loads, they must either be turned off slowly, or be provided with a high level of back EMF protection. If adequate back EMF protection cannot be provided using the integrated circuit process chosen, then external discrete transistors should be used. The transistors are never driven at the same time as the image sensor is used. This is to avoid voltage fluctuations and hot spots affecting the image quality. Further, the transistors are located as far away from the sensor as possible.

[0123] A standard JTAG (Joint Test Action Group) interface 228 is included in the ICP for testing purposes and for interrogation by the refill station. Due to the complexity of the integrated circuit, a variety of testing techniques are required, including BIST (Built In Self Test) and functional block isolation. An overhead of 10% in integrated circuit area is assumed for integrated circuit testing circuitry for the random logic portions. The overhead for the large arrays the image sensor and the DRAM is smaller.

[0124] The JTAG interface is also used for authentication of the refill station. This is included to ensure that the cameras are only refilled with quality paper and ink at a properly constructed refill station, thus preventing inferior quality refills from occurring. The camera must authenticate the refill station, rather than vice versa. The secure protocol is communicated to the refill station during the automated test procedure. Contact is made to four gold plated spots on the ICP/print head TAB by the refill station as the new ink is injected into the print head.

[0125]FIG. 16 illustrates a rear view of the next step in the construction process whilst FIG. 17 illustrates a front view.

[0126] Turning now to FIG. 16, the assembly of the camera system proceeds via first assembling the ink supply mechanism 40. The flex PCB is interconnected with batteries 84 only one of which is shown, which are inserted in the middle portion of a print roll 85 which is wrapped around a plastic former 86. An end cap 89 is provided at the other end of the print roll 85 so as to fasten the print roll and batteries firmly to the ink supply mechanism.

[0127] The solenoid coil is interconnected (not shown) to interconnects 97, 98 (FIG. 8) which include leaf spring ends for interconnection with electrical contacts on the Flex PCB so as to provide for electrical control of the solenoid.

[0128] Turning now to FIGS. 17-19 the next step in the construction process is the insertion of the relevant gear trains into the side of the camera chassis. FIG. 17 illustrates a front view, FIG. 18 illustrates a rear view and FIG. 19 also illustrates a rear view. The first gear train comprising gear wheels 22, 23 is utilised for driving the guillotine blade with the gear wheel 23 engaging the gear wheel 65 of FIG. 8. The second gear train comprising gear wheels 24, 25 and 26 engage one end of the print roller 61 of FIG. 8. As best indicated in FIG. 18, the gear wheels mate with corresponding pins on the surface of the chassis with the gear wheel 26 being snap fitted into corresponding mating hole 27.

[0129] Next, as illustrated in FIG. 20, the assembled platen unit 60 is then inserted between the print roll 85 and aluminium cutting blade 43.

[0130] Turning now to FIG. 21, by way of illumination, there is illustrated the electrically interactive components of the camera system. As noted previously, the components are based around a Flex PCB board and include a TAB film 58 which interconnects the printhead 102 with the image sensor and processing integrated circuit 48. Power is supplied by two AA type batteries 83, 84 and a paper drive stepper motor 16 is provided in addition to a rotary guillotine motor 17.

[0131] An optical element 31 is provided for snapping into a top portion of the chassis 12. The optical element 31 includes portions defining an optical view finder 32, 33 which are slotted into mating portions 35, 36 in view finder channel 37. Also provided in the optical element 31 is a lensing system 38 for magnification of the prints left number in addition to an optical pipe element 39 for piping light from the LED 5 for external display.

[0132] Turning next to FIG. 22, the assembled unit 90 is then inserted into a front outer case 91 which includes button 4 for activation of printouts.

[0133] Turning now to FIG. 23, next, the unit 90 is provided with a snap-on back cover 93 which includes a slot 6 and copy print button 7. A wrapper label containing instructions and advertising (not shown) is then wrapped around the outer surface of the camera system and pinch clamped to the cover by means of clamp strip 96 which can comprise a flexible plastic or rubber strip.

[0134] Subsequently, the preferred embodiment is ready for use as a one time use camera system that provides for instant output images on demand. It will be evident that the preferred embodiment further provides for a refillable camera system. A used camera can be collected and its outer plastic cases removed and recycled. A new paper roll and batteries can be added and the ink cartridge refilled. A series of automatic test routines can then be carried out to ensure that the printer is properly operational. Further, in order to ensure only authorised refills are conducted so as to enhance quality, routines in the on-integrated circuit program ROM can be executed such that the camera authenticates the refilling station using a secure protocol. Upon authentication, the camera can reset an internal paper count and an external case can be fitted on the camera system with a new outer label. Subsequent packing and shipping can then take place.

[0135] It will be further readily evident to those skilled in the art that the program ROM can be modified so as to allow for a variety of digital processing routines. In addition to the digitally enhanced photographs optimised for mainstream consumer preferences, various other models can readily be provided through mere re-programming of the program ROM. For example, a sepia classic old fashion style output can be provided through a remapping of the colour mapping function. A further alternative is to provide for black and white outputs again through a suitable colour remapping algorithm. Minimum colour can also be provided to add a touch of colour to black and white prints to produce the effect that was traditionally used to colourize black and white photos. Further, passport photo output can be provided through suitable address remappings within the address generators. Further, edge filters can be utilised as is known in the field of image processing to produce sketched art styles. Further, classic wedding borders and designs can be placed around an output image in addition to the provision of relevant clip arts. For example, a wedding style camera might be provided. Further, a panoramic mode can be provided so as to output the well known panoramic format of images. Further, a postcard style output can be provided through the printing of postcards including postage on the back of a print roll surface. Further, cliparts can be provided for special events such as Halloween, Christmas etc. Further, kaleidoscopic effects can be provided through address remappings and wild colour effects can be provided through remapping of the colour lookup table. Many other forms of special event cameras can be provided for example, cameras dedicated to the Olympics, movie tie-ins, advertising and other special events.

[0136] The operational mode of the camera can be programmed so that upon the depressing of the take photo a first image is sampled by the sensor array to determine irrelevant parameters. Next a second image is again captured which is utilised for the output. The captured image is then manipulated in accordance with any special requirements before being initially output on the paper roll. The LED light is then activated for a predetermined time during which the DRAM is refreshed so as to retain the image. If the print copy button is depressed during this predetermined time interval, a further copy of the photo is output. After the predetermined time interval where no use of the camera has occurred, the onboard CPU shuts down all power to the camera system until such time as the take button is again activated. In this way, substantial power savings can be realized.

[0137] Ink Jet Technologies

[0138] The embodiments of the invention use an ink jet printer type device. Of course many different devices could be used. However presently popular ink jet printing technologies are unlikely to be suitable.

[0139] The most significant problem with thermal inkjet is power consumption. This is approximately 100 times that required for high speed, and stems from the energy-inefficient means of drop ejection. This involves the rapid boiling of water to produce a vapor bubble which expels the ink. Water has a very high heat capacity, and must be superheated in thermal inkjet applications. This leads to an efficiency of around 0.02%, from electricity input to drop momentum (and increased surface area) out.

[0140] The most significant problem with piezoelectric inkjet is size and cost. Piezoelectric crystals have a very small deflection at reasonable drive voltages, and therefore require a large area for each nozzle. Also, each piezoelectric actuator must be connected to its drive circuit on a separate substrate. This is not a significant problem at the current limit of around 300 nozzles per print head, but is a major impediment to the fabrication of pagewide print heads with 19,200 nozzles.

[0141] Ideally, the inkjet technologies used meet the stringent requirements of in-camera digital color printing and other high quality, high speed, low cost printing applications. To meet the requirements of digital photography, new inkjet technologies have been created. The target features include:

[0142] low power (less than 10 Watts)

[0143] high resolution capability (1,600 dpi or more)

[0144] photographic quality output

[0145] low manufacturing cost

[0146] small size (pagewidth times minimum cross section)

[0147] high speed (<2 seconds per page).

[0148] All of these features can be met or exceeded by the inkjet systems described below with differing levels of difficulty. 45 different inkjet technologies have been developed by the Assignee to give a wide range of choices for high volume manufacture. These technologies form part of separate applications assigned to the present Assignee as set out in the table below.

[0149] The inkjet designs shown here are suitable for a wide range of digital printing systems, from battery powered one-time use digital cameras, through to desktop and network printers, and through to commercial printing systems

[0150] For ease of manufacture using standard process equipment, the print head is designed to be a monolithic 0.5 micron CMOS integrated circuit with MEMS post processing. For color photographic applications, the print head is 100 mm long, with a width which depends upon the inkjet type. The smallest print head designed is IJ38, which is 0.35 mm wide, giving a integrated circuit area of 35 square mm. The print heads each contain 19,200 nozzles plus data and control circuitry.

[0151] Ink is supplied to the back of the print head by injection molded plastic ink channels. The molding requires 50 micron features, which can be created using a lithographically micromachined insert in a standard injection molding tool. Ink flows through holes etched through the wafer to the nozzle chambers fabricated on the front surface of the wafer. The print head is connected to the camera circuitry by tape automated bonding.

[0152] Cross-Referenced Applications

[0153] The following table is a guide to cross-referenced patent applications filed concurrently herewith and discussed hereinafter with the reference being utilized in subsequent tables when referring to a particular case: Docket No. Reference Title IJ01US IJ01 Radiant Plunger Ink Jet Printer IJ02US IJ02 Electrostatic Ink Jet Printer IJ03US IJ03 Planar Thermoelastic Bend Actuator Ink Jet IJ04US IJ04 Stacked Electrostatic Ink Jet Printer IJ05US IJ05 Reverse Spring Lever Ink Jet Printer IJ06US IJ06 Paddle Type Ink Jet Printer IJ07US IJ07 Permanent Magnet Electromagnetic Ink Jet Printer IJ08US IJ08 Planar Swing Grill Electromagnetic Ink Jet Printer IJ09US IJ09 Pump Action Refill Ink Jet Printer IJ10US IJ10 Pulsed Magnetic Field Ink Jet Printer IJ11US IJ11 Two Plate Reverse Firing Electromagnetic Ink Jet Printer IJ12US IJ12 Linear Stepper Actuator Ink Jet Printer IJ13US IJ13 Gear Driven Shutter Ink Jet Printer IJ14US IJ14 Tapered Magnetic Pole Electromagnetic Ink Jet Printer IJ15US IJ15 Linear Spring Electromagnetic Grill Ink Jet Printer IJ16US IJ16 Lorenz Diaphragm Electromagnetic Ink Jet Printer IJ17US IJ17 PTFE Surface Shooting Shuttered Oscillating Pressure Ink Jet Printer IJ18US IJ18 Buckle Grip Oscillating Pressure Ink Jet Printer IJ19US IJ19 Shutter Based Ink Jet Printer IJ20US IJ20 Curling Calyx Thermoelastic Ink Jet Printer IJ21US IJ21 Thermal Actuated Ink Jet Printer IJ22US IJ22 Iris Motion Ink Jet Printer IJ23US IJ23 Direct Firing Thermal Bend Actuator Ink Jet Printer IJ24US IJ24 Conductive PTFE Ben Activator Vented Ink Jet Printer IJ25US IJ25 Magnetostrictive Ink Jet Printer IJ26US IJ26 Shape Memory Alloy Ink Jet Printer IJ27US IJ27 Buckle Plate Ink Jet Printer IJ28US IJ28 Thermal Elastic Rotary Impeller Ink Jet Printer IJ29US IJ29 Thermoelastic Bend Actuator Ink Jet Printer IJ30US IJ30 Thermoelastic Bend Actuator Using PTFE and Corrugated Copper Ink Jet Printer IJ31US IJ31 Bend Actuator Direct Ink Supply Ink Jet Printer IJ32US IJ32 A High Young's Modulus Thermoelastic Ink Jet Printer IJ33US IJ33 Thermally actuated slotted chamber wall ink jet printer IJ34US IJ34 Ink Jet Printer having a thermal actuator comprising an external coiled spring IJ35US IJ35 Trough Container Ink Jet Printer IJ36US IJ36 Dual Chamber Single Vertical Actuator Ink Jet IJ37US IJ37 Dual Nozzle Single Horizontal Fulcrum Actuator Ink Jet IJ38US IJ38 Dual Nozzle Single Horizontal Actuator Ink Jet IJ39US IJ39 A single bend actuator cupped paddle ink jet printing device IJ40US IJ40 A thermally actuated ink jet printer having a series of thermal actuator units IJ41US IJ41 A thermally actuated ink jet printer including a tapered heater element IJ42US IJ42 Radial Back-Curling Thermoelastic Ink Jet IJ43US IJ43 Inverted Radial Back-Curling Thermoelastic Ink Jet IJ44US IJ44 Surface bend actuator vented ink supply ink jet printer IJ45US IJ45 Coil Acutuated Magnetic Plate Ink Jet Printer

[0154] Tables of Drop-on-Demand Inkjets

[0155] Eleven important characteristics of the fundamental operation of individual ink-jet nozzles have been identified. These characteristics are largely orthogonal, and so can be elucidated as an eleven dimensional matrix. Most of the eleven axes of this matrix include entries developed by the present assignee.

[0156] The following tables form the axes of an eleven dimensional table of inkjet types.

[0157] Actuator mechanism (18 types)

[0158] Basic operation mode (7 types)

[0159] Auxiliary mechanism (8 types)

[0160] Actuator amplification or modification method (17 types)

[0161] Actuator motion (19 types)

[0162] Nozzle refill method (4 types)

[0163] Method of restricting back-flow through inlet (10 types)

[0164] Nozzle clearing method (9 types)

[0165] Nozzle plate construction (9 types)

[0166] Drop ejection direction (5 types)

[0167] Ink type (7 types)

[0168] The complete eleven dimensional table represented by these axes contains 36.9 billion possible configurations of inkjet nozzle. While not all of the possible combinations result in a viable inkjet technology, many million configurations are viable. It is clearly impractical to elucidate all of the possible configurations. Instead, certain inkjet types have been investigated in detail. These are designated IJ01 to IJ45 above.

[0169] Other inkjet configurations can readily be derived from these 45 examples by substituting alternative configurations along one or more of the 11 axes. Most of the IJ01 to IJ45 examples can be made into inkjet print heads with characteristics superior to any currently available inkjet technology.

[0170] Where there are prior art examples known to the inventor, one or more of these examples are listed in the examples column of the tables below. The IJ01 to IJ45 series are also listed in the examples column. In some cases, a printer may be listed more than once in a table, where it shares characteristics with more than one entry.

[0171] Suitable applications include: Home printers, Office network printers, Short run digital printers, Commercial print systems, Fabric printers, Pocket printers, Internet WWW printers, Video printers, Medical imaging, Wide format printers, Notebook PC printers, Fax machines, Industrial printing systems, Photocopiers, Photographic minilabs etc.

[0172] The information associated with the aforementioned 11 dimensional matrix are set out in the following tables.

[0173] Actuator Mechanism (Applied Only to Selected Ink Drops) Actu- ator Mech- anism Description Advantages Disadvantages Examples Thermal An electrothermal heater heats the 1) Large force generated 6) High power 16) Canon bubble ink to above boiling point, 2) Simple construction 7) Ink carrier limited to water Bubblejet 1979 Endo transferring significant heat to the 3) No moving parts 8) Low efficiency et al GB patent aqueous ink. A bubble nucleates and 4) Fast operation 9) High temperatures required 2,007,162 quickly forms, expelling the ink. 5) Small integrated circuit area 10) High mechanical stress 17) Xerox heater-in- The efficiency of the process is low, required for actuator 11) Unusual materials required pit 1990 Hawkins et with typically less than 0.05% of the 12) Large drive transistors al U.S. Pat. No. electrical energy being transformed 13) Cavitation causes actuator failure 4,899,181 into kinetic energy of the drop. 14) Kogation reduces bubble 18) Hewlett-Packard TIJ formation 1982 Vaught et al 15) Large print heads are difficult to U.S. Pat. No. 4,490,728 fabricate Piezo- A piezoelectric crystal such as lead 19) Low power 23) Very large area required for 28) Kyser et al electric lanthanum zirconate (PZT) is consumption actuator U.S. Pat. No. 3,946,398 electrically activated, and either 20) Many ink types can be 24) Difficult to integrate with 29) Zoltan U.S. Pat. No. expands, shears, or bends to apply used electronics 3,683,212 pressure to the ink, ejecting drops. 21) Fast operation 25) High voltage drive transistors 30) 1973 Stemme 22) High efficiency required U.S. Pat. No. 3,747,120 26) Full pagewidth print heads 31) Epson Stylus impractical due to actuator size 32) Tektronix 27) Requires electrical poling in high 33) IJ04 field strengths during manufacture Electro- An electric field is used to activate 34) Low power 39) Low maximum strain (approx. 44) Seiko Epson, strictive electrostriction in relaxor materials consumption 0.01%) Usui et all JP such as lead lanthanum zirconate 35) Many ink types can be 40) Large area required for actuator 253401/96 titanate (PLZT) or lead magnesium used due to low strain 45) IJ04 niobate (PMN). 36) Low thermal 41) Response speed is marginal (˜10 μs) expansion 42) High voltage drive transistors 37) Electric field strength required required (approx. 3.5 V/μm) 43) Full pagewidth print heads can be generated without impractical due to actuator size difficulty 38) Does not require electrical poling Ferro- An electric field is used to induce a 46) Low power 52) Difficult to integrate with 55) IJ04 electric phase transition between the consumption electronics antiferroelectric (AFE) and 47) Many ink types can be 53) Unusual materials such as ferroelectric (FE) phase. Perovskite used PLZSnT are required materials such as tin modified lead 48) Fast operation (<1 μs) 54) Actuators require a large area lanthanum zirconate titanate 49) Relatively high (PLZSnT) exhibit large strains of up longitudinal strain to 1% associated with the AFE to FE 50) High efficiency phase transition. 51) Electric field strength of around 3 V/μm can be readily provided Electro- Conductive plates are separated by a 56) Low power 59) Difficult to operate electrostatic 64) IJ02, IJ04 static compressible or fluid dielectric consumption devices in an aqueous environment plates (usually air). Upon application of a 57) Many ink types can be 60) The electrostatic actuator will voltage, the plates attract each other used normally need to be separated from the and displace ink, causing drop 58) Fast operation ink ejection. The conductive plates may 61) Very large area required to be in a comb or honeycomb achieve high forces structure, or stacked to increase the 62) High voltage drive transistors surface area and therefore the force. may be required 63) Full pagewidth print heads are not competitive due to actuator size Electro- A strong electric field is applied to 65) Low current 67) High voltage required 72) 1989 Saito et al, static the ink, whereupon electrostatic consumption 68) May be damaged by sparks due to U.S. Pat. No. 4,799,068 pull on attraction accelerates the ink towards 66) Low temperature air breakdown 73) 1989 Miura et ink the print medium. 69) Required field strength increases al, U.S. Pat. No. as the drop size decreases 4,810,954 70) High voltage drive transistors 74) Tone-jet required 71) Electrostatic field attracts dust Perma- An electromagnet directly attracts a 75) Low power 80) Complex fabrication 86) IJ07, IJ10 nent permanent magnet, displacing ink consumption 81) Permanent magnetic material magnet and causing drop ejection. Rare earth 76) Many ink types can be such as Neodymium Iron Boron electro- magnets with a field strength around used (NdFeB) required. mag- 1 Tesla can be used. Examples are: 77) Fast operation 82) High local currents required netic Samarium Cobalt (SaCo) and 78) High efficiency 83) Copper metalization should be magnetic materials in the neodymium 79) Easy extension from used for long electromigration lifetime iron boron family (NdFeB, single nozzles to pagewidth and low resistivity NdDyFeBNb, NdDyFeB, etc) print heads 84) Pigmented inks are usually infeasible 85) Operating temperature limited to the Curie temperature (around 540 K) Soft A solenoid induced a magnetic field 87) Low power 92) Complex fabrication 98) IJ01, IJ05, IJ08, mag- in a soft magnetic core or yoke consumption 93) Materials not usually present in a IJ10 netic fabricated from a ferrous material 88) Many ink types can be CMOS fab such as NiFe, CoNiFe, or 99) IJ12, IJ14, IJ15, core such as electroplated iron alloys such used CoFe are required IJ17 electro- as CoNiFe [1], CoFe, or NiFe alloys. 89) Fast operation 94) High local currents required mag- Typically, the soft magnetic material 90) High efficiency 95) Copper metalization should be netic is in two parts, which are normally 91) Easy extension from used for long electromigration lifetime held apart by a spring. When the single nozzles to pagewidth and low resistivity solenoid is actuated, the two parts print heads 96) Electroplating is required attract, displacing the ink. 97) High saturation flux density is required (2.0-2.1 T is achievable with CoNiFe[1]) Mag- The Lorenz force acting on a current 100) Low power 105) Force acts as a twisting motion 110) IJ06, IJ11, IJ13, netic carrying wire in a magnetic field is consumption 106) Typically, only a quarter of the IJ16 Lorenz utilized. 101) Many ink types can be solenoid length provides force in a force This allows the magnetic field to be used useful direction supplied externally to the print head, 102) Fast operation 107) High local currents required for example with rare earth 103) High efficiency 108) Copper metalization should be permanent magnets. 104) Easy extension from used for long electromigration lifetime Only the current carrying wire need single nozzles to pagewidth and low resistivity be fabricated on the print-head, print heads 109) Pigmented inks are usually simplifying materials requirements. infeasible Mag- The actuator uses the giant 111) Many ink types can be 115) Force acts as a twisting motion 120) Fischenbeck, neto- magnetostrictive effect of materials used 116) Unusual materials such as U.S. Pat. No. 4,032,929 striction such as Terfenol-D (an alloy of 112) Fast operation Terfenol-D are required 121) IJ25 terbium, dysprosium and iron 113) Easy extension from 117) High local currents required developed at the Naval Ordnance single nozzles to pagewidth 118) Copper metalization should be Laboratory, hence Ter-Fe-NOL). For print heads used for long electromigration lifetime best efficiency, the actuator should 114) High force is available and low resistivity be pre-stressed to approx. 8 MPa. 119) Pre-stressing may be required Surface Ink under positive pressure is held in 122) Low power 127) Requires supplementary force to 130) Silverbrook, EP tension a nozzle by surface tension. The consumption effect drop separation 0771 658 A2 and reduc- surface tension of the ink is reduced 123) Simple construction 128) Requires special ink surfactants related patent tion below the bubble threshold, causing 124) No unusual materials 129) Speed may be limited by applications the ink to egress from the nozzle. required in fabrication surfactant properties 125) High efficiency 126) Easy extension from single nozzles to pagewidth print heads Vis- The ink viscosity is locally reduced 131) Simple construction 134) Requires supplementary force to 139) Silverbrook, EP cosity to select which drops are to be 132) No unusual materials effect drop separation 0771 658 A2 and reduc- ejected. A viscosity reduction can be required in fabrication 135) Requires special ink viscosity related patent tion achieved electrothermally with most 133) Easy extension from properties applications inks, but special inks can be single nozzles to pagewidth 136) High speed is difficult to achieve engineered for a 100:1 viscosity print heads 137) Requires oscillating ink pressure reduction. 138) A high temperature difference (typically 80 degrees) is required Acous- An acoustic wave is generated and 140) Can operate without a 141) Complex drive circuitry 146) 1993 tic focussed upon the drop ejection nozzle plate 142) Complex fabrication Hadimioglu et al, region. 143) Low efficiency EUP 550,192 144) Poor control of drop position 147) 1993 Elrod et al, 145) Poor control of drop volume EUP 572,220 Ther- An actuator which relies upon 148) Low power 157) Efficient aqueous operation 160) IJ03, IJ09, IJ17, mo- differential thermal expansion upon consumption requires a thermal insulator on the hot IJ18 elastic Joule heating is used. 149) Many ink types can be side 161) IJ19, IJ20, IJ21, actuator used 158) Corrosion prevention can be IJ22 150) Simple planar difficult 162) IJ23, IJ24, IJ27, fabrication 159) Pigmented inks may be infeasible, IJ28 151) Small integrated as pigment particles may jam the bend 163) IJ29, IJ30, IJ31, circuit area required for actuator IJ32 each actuator 164) IJ33, IJ34, IJ35, 152) Fast operation IJ36 153) High efficiency 165) IJ37, IJ38, IJ39, 154) CMOS compatible IJ40 voltages and currents 166) IJ41 155) Standard MEMS processes can be used 156) Easy extension from single nozzles to pagewidth print heads High A material with a very high 167) High force can be 177) Requires special material (e.g. 181) IJ09, IJ17, IJ18, CTE coefficient of thermal expansion generated PTFE) IJ20 thermo- (CTE) such as 168) PTFE is a candidate 178) Requires a PTFE deposition 182) IJ21, IJ22, IJ23, elastic polytetrafluoroethylene (PTFE) is for low dielectric constant process, which is not yet standard in IJ24 actuator used. As high CTE materials are insulation in ULSI ULSI fabs 183) IJ27, IJ28, IJ29, usually non-conductive, a heater 169) Very low power 179) PTFE deposition cannot be IJ30 fabricated from a conductive material consumption followed with high temperature (above 184) IJ31, IJ42, IJ43, is incorporated. A 50 μm long PTFE 170) Many ink types can be 350° C.) processing IJ44 bend actuator with polysilicon heater used 180) Pigmented inks may be infeasible, and 15 mW power input can provide 171) Simple planar as pigment particles may jam the bend 180 μN force and 10 μm deflection. fabrication actuator Actuator motions include: 172) Small integrated Bend circuit area required for Push each actuator Buckle 173) Fast operation Rotate 174) High efficiency 175) CMOS compatible voltages and currents 176) Easy extension from single nozzles to pagewidth print heads Con- A polymer with a high coefficient of 185) High force can be 194) Requires special materials 199) IJ24 ductive thermal expansion (such as PTFE) is generated development (High CTE conductive polymer doped with conducting substances to 186) Very low power polymer) thermo- increase its conductivity to about 3 consumption 195) Requires a PTFE deposition elastic orders of magnitude below that of 187) Many ink types can be process, which is not yet standard in actuator copper. The conducting polymer used ULSI fabs expands when resistively heated. 188) Simple planar 196) PTFE deposition cannot be Examples of conducting dopants fabrication followed with high temperature (above include: 189) Small integrated 350° C.) processing Carbon nanotubes circuit area required for 197) Evaporation and CVD deposition Metal fibers each actuator techniques cannot be used Conductive polymers such as doped 190) Fast operation 198) Pigmented inks may be infeasible, polythiophene 191) High efficiency as pigment particles may jam the bend Carbon granules 192) CMOS compatible actuator voltages and currents 193) Easy extension from single nozzles to pagewidth print heads Shape A shape memory alloy such as TiNi 200) High force is available 206) Fatigue limits maximum number 213) IJ26 memory (also known as Nitinol —Nickel (stresses of hundreds of of cycles alloy Titanium alloy developed at the MPa) 207) Low strain (1%) is required to Naval Ordnance Laboratory) is 201) Large strain is extend fatigue resistance thermally switched between its weak available (more than 3%) 208) Cycle rate limited by heat martensitic state and its high stiffness 202) High corrosion removal austenic state. The shape of the resistance 209) Requires unusual materials (TiNi) actuator in its martensitic state is 203) Simple construction 210) The latent heat of transformation deformed relative to the austenic 204) Easy extension from must be provided shape. The shape change causes single nozzles to pagewidth 211) High current operation ejection of a drop. print heads 212) Requires pre-stressing to distort 205) Low voltage operation the martensitic state Linear Linear magnetic actuators include the 214) Linear Magnetic 218) Requires unusual semiconductor 222) IJ12 Mag- Linear Induction Actuator (LIA), actuators can be constructed materials such as soft magnetic alloys netic Linear Permanent Magnet with high thrust, long travel, (e.g. CoNiFe [1]) Actu- Synchronous Actuator (LPMSA), and high efficiency using 219) Some varieties also require ator Linear Reluctance Synchronous planar semiconductor permanent magnetic materials such as Actuator (LRSA), Linear Switched fabrication techniques Neodymium iron boron (NdFeB) Reluctance Actuator (LSRA), and the 215) Long actuator travel is 220) Requires complex multi-phase Linear Stepper Actuator (LSA). available drive circuitry 216) Medium force is 221) High current operation available 217) Low voltage operation

[0174] Basic Operation Mode Operational mode Description Advantages Disadvantages Examples Actuator This is the simplest mode of 223) Simple operation 227) Drop repetition rate is usually 230) Thermal inkjet directly pushes operation: the actuator directly 224) No external fields limited to less than 10 KHz. However, 231) Piezoelectric ink supplies sufficient kinetic energy to required this is not fundamental to the method, inkjet expel the drop. The drop must have a 225) Satellite drops can be but is related to the refill method 232) IJ01, IJ02, IJ03, sufficient velocity to overcome the avoided if drop velocity is normally used IJ04 surface tension. less than 4 m/s 228) All of the drop kinetic energy 233) IJ05, IJ06, IJ07, 226) Can be efficient, must be provided by the actuator IJ09 depending upon the actuator 229) Satellite drops usually form if 234) IJ11, IJ12, IJ14, used drop velocity is greater than 4.5 m/s IJ16 235) IJ20, IJ22, IJ23, IJ24 236) IJ25, IJ26, IJ27, IJ28 237) IJ29, IJ30, IJ31, IJ32 238) IJ33, IJ34, IJ35, IJ36 239) IJ37, IJ38, IJ39, IJ40 240) IJ41, IJ42, IJ43, IJ44 Proximity The drops to be printed are selected 241) Very simple print head 243) Requires close proximity between 246) Silverbrook, EP by some manner (e.g. thermally fabrication can be used the print head and the print media or 0771 658 A2 and induced surface tension reduction of 242) The drop selection transfer roller related patent pressurized ink). Selected drops are means does not need to 244) May require two print heads applications separated from the ink in the nozzle provide the energy required printing alternate rows of the image by contact with the print medium or a to separate the drop from 245) Monolithic color print heads are transfer roller. the nozzle difficult Electrostatic The drops to be printed are selected 247) Very simple print head 249) Requires very high electrostatic 252) Silverbrook, EP pull on ink by some manner (e.g. thermally fabrication can be used field 0771 658 A2 and induced surface tension reduction of 248) The drop selection 250) Electrostatic field for small nozzle related patent pressurized ink). Selected drops are means does not need to sizes is above air breakdown applications separated from the ink in the nozzle provide the energy required 251) Electrostatic field may attract dust 253) Tone-Jet by a strong electric field. to separate the drop from the nozzle Magnetic pull The drops to be printed are selected 254) Very simple print head 256) Requires magnetic ink 259) Silverbrook, EP on ink by some manner (e.g. thermally fabrication can be used 257) Ink colors other than black are 0771 658 A2 and induced surface tension reduction of 255) The drop selection difficult related patent pressurized ink). Selected drops are means does not need to 258) Requires very high magnetic applications separated from the ink in the nozzle provide the energy required fields by a strong magnetic field acting on to separate the drop from the magnetic ink. the nozzle Shutter The actuator moves a shutter to block 260) High speed (>50 KHz) 263) Moving parts are required 267) IJ13, IJ17, IJ21 ink flow to the nozzle. The ink operation can be achieved 264) Requires ink pressure modulator pressure is pulsed at a multiple of the due to reduced refill time 265) Friction and wear must be drop ejection frequency. 261) Drop timing can be considered very accurate 266) Stiction is possible 262) The actuator energy can be very low Shuttered grill The actuator moves a shutter to block 268) Actuators with small 271) Moving parts are required 275) IJ08, IJ15, IJ18, ink flow through a grill to the nozzle. travel can be used 272) Requires ink pressure modulator IJ19 The shutter movement need only be 269) Actuators with small 273) Friction and wear must be equal to the width of the grill holes. force can be used considered 270) High speed (>50 KHz) 274) Stiction is possible operation can be achieved Pulsed A pulsed magnetic field attracts an 276) Extremely low energy 278) Requires an external pulsed 281) IJ10 magnetic pull ‘ink pusher’ at the drop ejection operation is possible magnetic field on ink frequency. An actuator controls a 277) No heat dissipation 279) Requires special materials for pusher catch, which prevents the ink pusher problems both the actuator and the ink pusher from moving when a drop is not to be 280) Complex construction ejected.

[0175] Auxiliary Mechanism (Applied to All Nozzles) Auxiliary Mechanism Description Advantages Disadvantages Examples None The actuator directly fires the ink 282) Simplicity of 285) Drop ejection energy must be 286) Most inkjets, drop, and there is no external field or construction supplied by individual nozzle actuator including other mechanism required. 283) Simplicity of operation piezoelectric and 284) Small physical size thermal bubble. 287) IJ01-IJ07, IJ09, IJ11 288) IJ12, IJ14, IJ20, IJ22 289) IJ23-IJ45 Oscillating ink The ink pressure oscillates, providing 290) Oscillating ink 293) Requires external ink pressure 296) Silverbrook, EP pressure much of the drop ejection energy. pressure can provide a refill oscillator 0771 658 A2 and (including The actuator selects which drops are pulse, allowing higher 294) Ink pressure phase and amplitude related patent acoustic to be fired by selectively blocking or operating speed must be carefully controlled applications stimulation) enabling nozzles. The ink pressure 291) The actuators may 295) Acoustic reflections in the ink 297) IJ08, IJ13, IJ15, oscillation may be achieved by operate with much lower chamber must be designed for IJ17 vibrating the print head, or preferably energy 298) IJ18, IJ19, IJ21 by an actuator in the ink supply. 292) Acoustic lenses can be used to focus the sound on the nozzles Media The print head is placed in close 299) Low power 302) Precision assembly required 305) Silverbrook, EP proximity proximity to the print medium. 300) High accuracy 303) Paper fibers may cause problems 0771 658 A2 and Selected drops protrude from the 301) Simple print head 304) Cannot print on rough substrates related patent print head further than unselected construction applications drops, and contact the print medium. The drop soaks into the medium fast enough to cause drop separation. Transfer roller Drops are printed to a transfer roller 306) High accuracy 309) Bulky 312) Silverbrook, EP instead of straight to the print 307) Wide range of print 310) Expensive 0771 658 A2 and medium. A transfer roller can also be substrates can be used 311) Complex construction related patent used for proximity drop separation. 308) Ink can be dried on the applications transfer roller 313) Tektronix hot melt piezoelectric inkjet 314) Any of the IJ series Electrostatic An electric field is used to accelerate 315) Low power 317) Field strength required for 318) Silverbrook, EP selected drops towards the print 316) Simple print head separation of small drops is near or 0771 658 A2 and medium. construction above air breakdown related patent applications 319) Tone-Jet Direct A magnetic field is used to accelerate 320) Low power 322) Requires magnetic ink 324) Silverbrook, EP magnetic field selected drops of magnetic ink 321) Simple print head 323) Requires strong magnetic field 0771 658 A2 and towards the print medium. construction related patent applications Cross magnetic The print head is placed in a constant 325) Does not require 326) Requires external magnet 328) IJ06, IJ16 field magnetic field. The Lorenz force in a magnetic materials to be 327) Current densities may be high, current carrying wire is used to move integrated in the print head resulting in electromigration problems the actuator. manufacturing process Pulsed A pulsed magnetic field is used to 329) Very low power 331) Complex print head construction 333) IJ10 magnetic field cyclically attract a paddle, which operation is possible 332) Magnetic materials required in pushes on the ink. A small actuator 330) Small print head size print head moves a catch, which selectively prevents the paddle from moving.

[0176] Actuator Amplification or Modification Method Actuator amplification Description Advantages Disadvantages Examples None No actuator mechanical amplification 334) Operational simplicity 335) Many actuator mechanisms have 336) Thermal Bubble is used. The actuator directly drives insufficient travel, or insufficient force, Inkjet the drop ejection process. to efficiently drive the drop ejection 337) IJ01, IJ02, IJ06, process IJ07 338) IJ16, IJ25, IJ26 Differential An actuator material expands more 339) Provides greater travel 341) High stresses are involved 344) Piezoelectric expansion bend on one side than on the other. The in a reduced print head area 342) Care must be taken that the 345) IJ03, IJ09, actuator expansion may be thermal, 340) The bend actuator materials do not delaminate IJ17-IJ24 piezoelectric, magnetostrictive, or converts a high force low 343) Residual bend resulting from high 346) IJ27, IJ29-IJ39, other mechanism. travel actuator mechanism temperature or high stress during IJ42, to high travel, lower force formation 347) IJ43, IJ44 mechanism. Transient bend A trilayer bend actuator where the 348) Very good 351) High stresses are involved 353) IJ40, IJ41 actuator two outside layers are identical. This temperature stability 352) Care must be taken that the cancels bend due to ambient 349) High speed, as a new materials do not delaminate temperature and residual stress. The drop can be fired before actuator only responds to transient heat dissipates heating of one side or the other. 350) Cancels residual stress of formation Actuator stack A series of thin actuators are stacked. 354) Increased travel 356) Increased fabrication complexity 358) Some This can be appropriate where 355) Reduced drive voltage 357) Increased possibility of short piezoelectric ink jets actuators require high electric field circuits due to pinholes 359) IJ04 strength, such as electrostatic and piezoelectric actuators. Multiple Multiple smaller actuators are used 360) Increases the force 362) Actuator forces may not add 363) IJ12, IJ13, IJ18, actuators simultaneously to move the ink. Each available from an actuator linearly, reducing efficiency IJ20 actuator need provide only a portion 361) Multiple actuators can 364) IJ22, IJ28, IJ42, of the force required. be positioned to control ink IJ43 flow accurately Linear Spring A linear spring is used to transform a 365) Matches low travel 367) Requires print head area for the 368) IJ15 motion with small travel and high actuator with higher travel spring force into a longer travel, lower force requirements motion. 366) Non-contact method of motion transformation Reverse spring The actuator loads a spring. When 369) Better coupling to the 370) Fabrication complexity 372) IJ05, IJ11 the actuator is turned off, the spring ink 371) High stress in the spring releases. This can reverse the force/distance curve of the actuator to make it compatible with the force/time requirements of the drop ejection. Coiled actuator A bend actuator is coiled to provide 373) Increases travel 376) Generally restricted to planar 377) IJ17, IJ21, IJ34, greater travel in a reduced integrated 374) Reduces integrated implementations due to extreme IJ35 circuit area. circuit area fabrication difficulty in other 375) Planar orientations. implementations are relatively easy to fabricate. Flexure bend A bend actuator has a small region 378) Simple means of 379) Care must be taken not to exceed 382) IJ10, IJ19, IJ33 actuator near the fixture point, which flexes increasing travel of a bend the elastic limit in the flexure area much more readily than the actuator 380) Stress distribution is very uneven remainder of the actuator. The 381) Difficult to accurately model with actuator flexing is effectively finite element analysis converted from an even coiling to an angular bend, resulting in greater travel of the actuator tip. Gears Gears can be used to increase travel 383) Low force, low travel 385) Moving parts are required 390) IJ13 at the expense of duration. Circular actuators can be used 386) Several actuator cycles are gears, rack and pinion, ratchets, and 384) Can be fabricated required other gearing methods can be used. using standard surface 387) More complex drive electronics MEMS processes 388) Complex construction 389) Friction, friction, and wear are possible Catch The actuator controls a small catch. 391) Very low actuator 393) Complex construction 396) IJ10 The catch either enables or disables energy 394) Requires external force movement of an ink pusher that is 392) Very small actuator 395) Unsuitable for pigmented inks controlled in a bulk manner. size Buckle plate A buckle plate can be used to change 397) Very fast movement 398) Must stay within elastic limits of 401) S. Hirata et al, a slow actuator into a fast motion. It achievable the materials for long device life “An Ink-jet Head ...”, can also convert a high force, low 399) High stresses involved Proc. IEEE MEMS, travel actuator into a high travel, 400) Generally high power Feb. 1996, pp 418-423. medium force motion. requirement 402) IJ18, IJ27 Tapered A tapered magnetic pole can increase 403) Linearizes the 404) Complex construction 405) IJ14 magnetic pole travel at the expense of force. magnetic force/distance curve Lever A lever and fulcrum is used to 406) Matches low travel 408) High stress around the fulcrum 409) IJ32, IJ36, IJ37 transform a motion with small travel actuator with higher travel and high force into a motion with requirements longer travel and lower force. The 407) Fulcrum area has no lever can also reverse the direction of linear movement, and can travel. be used for a fluid seal Rotary impeller The actuator is connected to a rotary 410) High mechanical 412) Complex construction 414) IJ28 impeller. A small angular deflection advantage 413) Unsuitable for pigmented inks of the actuator results in a rotation of 411) The ratio of force to the impeller vanes, which push the travel of the actuator can be ink against stationary vanes and out matched to the nozzle of the nozzle. requirements by varying the number of impeller vanes Acoustic lens A refractive or diffractive (e.g. zone 415) No moving parts 416) Large area required 418) 1993 plate) acoustic lens is used to 417) Only relevant for acoustic ink jets Hadimioglu et al, concentrate sound waves. EUP 550,192 419) 1993 Elrod et al, EUP 572,220 Sharp A sharp point is used to concentrate 420) Simple construction 421) Difficult to fabricate using 423) Tone-jet conductive an electrostatic field. standard VLSI processes for a surface point ejecting ink-jet 422) Only relevant for electrostatic ink jets

[0177] Actuator Motion Actuator motion Description Advantages Disadvantages Examples Volume The volume of the actuator changes, 424) Simple construction in 425) High energy is typically required 426) Hewlett- expansion pushing the ink in all directions. the case of thermal ink jet to achieve volume expansion. This Packard Thermal leads to thermal stress, cavitation, and Inkjet kogation in thermal ink jet 427) Canon implementations Bubblejet Linear, normal The actuator moves in a direction 428) Efficient coupling to 429) High fabrication complexity may 430) IJ01, IJ02, IJ04, to integrated normal to the print head surface. The ink drops ejected normal to be required to achieve perpendicular IJ07 circuit surface nozzle is typically in the line of the surface motion 431) IJ11, IJ14 movement. Linear, parallel The actuator moves parallel to the 432) Suitable for planar 433) Fabrication complexity 436) IJ12, IJ13, IJ15, to integrated print head surface. Drop ejection may fabrication 434) Friction IJ33, circuit surface still be normal to the surface. 435) Stiction 437) IJ34, IJ35, IJ36 Membrane An actuator with a high force but 438) The effective area of 439) Fabrication complexity 442) 1982 Howkins push small area is used to push a stiff the actuator becomes the 440) Actuator size U.S. Pat. No. 4,459,601 membrane that is in contact with the membrane area 441) Difficulty of integration in a ink. VLSI process Rotary The actuator causes the rotation of 443) Rotary levers may be 445) Device complexity 447) IJ05, IJ08, IJ13, some element, such a grill or used to increase travel 446) May have friction at a pivot point IJ28 impeller 444) Small integrated circuit area requirements Bend The actuator bends when energized. 448) A very small change 449) Requires the actuator to be made 450) 1970 Kyser et al This may be due to differential in dimensions can be from at least two distinct layers, or to U.S. Pat. No. 3,946,398 thermal expansion, piezoelectric converted to a large motion. have a thermal difference across the 451) 1973 Stemme expansion, magnetostriction, or other actuator U.S. Pat. No. 3,747,120 form of relative dimensional change. 452) IJ03, IJ09, IJ10, IJ19 453) IJ23, IJ24, IJ25, IJ29 454) IJ30, IJ31, IJ33, IJ34 455) IJ35 Swivel The actuator swivels around a central 456) Allows operation 458) Inefficient coupling to the ink 459) IJ06 pivot. This motion is suitable where where the net linear force motion there are opposite forces applied to on the paddle is zero opposite sides of the paddle, e.g. 457) Small integrated Lorenz force. circuit area requirements Straighten The actuator is normally bent, and 460) Can be used with 461) Requires careful balance of 462) IJ26, IJ32 straightens when energized. shape memory alloys where stresses to ensure that the quiescent the austenic phase is planar bend is accurate Double bend The actuator bends in one direction 463) One actuator can be 466) Difficult to make the drops 468) IJ36, IJ37, IJ38 when one element is energized, and used to power two nozzles. ejected by both bend directions bends the other way when another 464) Reduced integrated identical. element is energized. circuit size. 467) A small efficiency loss compared 465) Not sensitive to to equivalent single bend actuators. ambient temperature Shear Energizing the actuator causes a 469) Can increase the 470) Not readily applicable to other 471) 1985 Fishbeck shear motion in the actuator material. effective travel of actuator mechanisms U.S. Pat. No. 4,584,590 piezoelectric actuators Radial The actuator squeezes an ink 472) Relatively easy to 473) High force required 476) 1970 Zoltan constriction reservoir, forcing ink from a fabricate single nozzles 474) Inefficient U.S. Pat. No. 3,683,212 constricted nozzle. from glass tubing as 475) Difficult to integrate with VLSI macroscopic structures processes Coil/uncoil A coiled actuator uncoils or coils 477) Easy to fabricate as a 479) Difficult to fabricate for non- 481) IJ17, IJ21, IJ34, more tightly. The motion of the free planar VLSI process planar devices IJ35 end of the actuator ejects the ink. 478) Small area required, 480) Poor out-of-plane stiffness therefore low cost Bow The actuator bows (or buckles) in the 482) Can increase the speed 484) Maximum travel is constrained 486) IJ16, IJ18, IJ27 middle when energized. of travel 485) High force required 483) Mechanically rigid Push-Pull Two actuators control a shutter. One 487) The structure is pinned 488) Not readily suitable for inkjets 489) IJ18 actuator pulls the shutter, and the at both ends, so has a high which directly push the ink other pushes it. out-of-plane rigidity Curl inwards A set of actuators curl inwards to 490) Good fluid flow to the 491) Design complexity 492) IJ20, IJ42 reduce the volume of ink that they region behind the actuator enclose. increases efficiency Curl outwards A set of actuators curl outwards, 493) Relatively simple 494) Relatively large integrated circuit 495) IJ43 pressurizing ink in a chamber construction area surrounding the actuators, and expelling ink from a nozzle in the chamber. Iris Multiple vanes enclose a volume of 496) High efficiency 498) High fabrication complexity 500) IJ22 ink. These simultaneously rotate, 497) Small integrated 499) Not suitable for pigmented inks reducing the volume between the circuit area vanes. Acoustic The actuator vibrates at a high 501) The actuator can be 502) Large area required for efficient 506) 1993 vibration frequency. physically distant from the operation at useful frequencies Hadimioglu et al, ink 503) Acoustic coupling and crosstalk EUP 550,192 504) Complex drive circuitry 507) 1993 Elrod et al, 505) Poor control of drop volume and EUP 572,220 position None In various ink jet designs the actuator 508) No moving parts 509) Various other tradeoffs are 510) Silverbrook, EP does not move. required to eliminate moving parts 0771 658 A2 and related patent applications 511) Tone-jet

[0178] Nozzle Refill Method Nozzle refill method Description Advantages Disadvantages Examples Surface tension After the actuator is energized, it 512) Fabrication simplicity 514) Low speed 517) Thermal inkjet typically returns rapidly to its normal 513) Operational simplicity 515) Surface tension force relatively 518) Piezoelectric position. This rapid return sucks in small compared to actuator force inkjet air through the nozzle opening. The 516) Long refill time usually 519) IJ01-IJ07, IJ10-IJ14 ink surface tension at the nozzle then dominates the total repetition rate 520) IJ16, IJ20, IJ22-IJ45 exerts a small force restoring the meniscus to a minimum area. Shuttered Ink to the nozzle chamber is provided 521) High speed 523) Requires common ink pressure 525) IJ08, IJ13, IJ15, oscillating ink at a pressure that oscillates at twice 522) Low actuator energy, oscillator IJ17 pressure the drop ejection frequency. When a as the actuator need only 524) May not be suitable for 526) IJ18, IJ19, IJ21 drop is to be ejected, the shutter is open or close the shutter, pigmented inks opened for 3 half cycles: drop instead of ejecting the ink ejection, actuator return, and refill. drop Refill actuator After the main actuator has ejected a 527) High speed, as the 528) Requires two independent 529) IJ09 drop a second (refill) actuator is nozzle is actively refilled actuators per nozzle energized. The refill actuator pushes ink into the nozzle chamber. The refill actuator returns slowly, to prevent its return from emptying the chamber again. Positive ink The ink is held a slight positive 530) High refill rate, 531) Surface spill must be prevented 533) Silverbrook, EP pressure pressure. After the ink drop is therefore a high drop 532) Highly hydrophobic print head 0771 658 A2 and ejected, the nozzle chamber fills repetition rate is possible surfaces are required related patent quickly as surface tension and ink applications pressure both operate to refill the 534) Alternative for: nozzle. 535) IJ01-IJ07, IJ10-IJ14 536) IJ16, IJ20, IJ22-IJ45

[0179] Method of Restricting Back-Flow Through Inlet Inlet back-flow restriction method Description Advantages Disadvantages Examples Long inlet The ink inlet channel to the nozzle 537) Design simplicity 540) Restricts refill rate 543) Thermal inkjet channel chamber is made long and relatively 538) Operational simplicity 541) May result in a relatively large 544) Piezoelectric narrow, relying on viscous drag to 539) Reduces crosstalk integrated circuit area inkjet reduce inlet back-flow. 542) Only partially effective 545) IJ42, IJ43 Positive ink The ink is under a positive pressure, 546) Drop selection and 548) Requires a method (such as a 549) Silverbrook, EP pressure so that in the quiescent state some of separation forces can be nozzle rim or effective hydrophobizing, 0771 658 A2 and the ink drop already protrudes from reduced or both) to prevent flooding of the related patent the nozzle. 547) Fast refill time ejection surface of the print head. applications This reduces the pressure in the 550) Possible nozzle chamber which is required to operation of the eject a certain volume of ink. The following: reduction in chamber pressure results 551) IJ01-IJ07, IJ09- in a reduction in ink pushed out IJ12 through the inlet. 552) IJ14, IJ16, IJ20, IJ22, 553) IJ23-IJ34, IJ36- IJ41 554) IJ44 Baffle One or more baffles are placed in the 555) The refill rate is not as 557) Design complexity 559) HP Thermal Ink inlet ink flow. When the actuator is restricted as the long inlet 558) May increase fabrication Jet energized, the rapid ink movement method. complexity (e.g. Tektronix hot melt 560) Tektronix creates eddies which restrict the flow 556) Reduces crosstalk Piezoelectric print heads). piezoelectric ink jet through the inlet. The slower refill process is unrestricted, and does not result in eddies. Flexible flap In this method recently disclosed by 561) Significantly reduces 562) Not applicable to most inkjet 565) Canon restricts inlet Canon, the expanding actuator back-flow for edge-shooter configurations (bubble) pushes on a flexible flap thermal ink jet devices 563) Increased fabrication complexity that restricts the inlet. 564) Inelastic deformation of polymer flap results in creep over extended use Inlet filter A filter is located between the ink 566) Additional advantage 568) Restricts refill rate 570) IJ04, IJ12, IJ24, inlet and the nozzle chamber. The of ink filtration 569) May result in complex IJ27 filter has a multitude of small holes 567) Ink filter may be construction 571) IJ29, IJ30 or slots, restricting ink flow. The fabricated with no filter also removes particles which additional process steps may block the nozzle. Small inlet The ink inlet channel to the nozzle 572) Design simplicity 573) Restricts refill rate 576) IJ02, IJ37, IJ44 compared to chamber has a substantially smaller 574) May result in a relatively large nozzle cross section than that of the nozzle, integrated circuit area resulting in easier ink egress out of 575) Only partially effective the nozzle than out of the inlet. Inlet shutter A secondary actuator controls the 577) Increases speed of the 578) Requires separate refill actuator 579) IJ09 position of a shutter, closing off the ink-jet print head operation and drive circuit ink inlet when the main actuator is energized. The inlet is The method avoids the problem of 580) Back-flow problem is 581) Requires careful design to 582) IJ01, IJ03, IJ05, located behind inlet back-flow by arranging the ink- eliminated minimize the negative pressure behind IJ06 the ink-pushing pushing surface of the actuator the paddle 583) IJ07, IJ10, IJ11, surface between the inlet and the nozzle. IJ14 584) IJ16, IJ22, IJ23, IJ25 585) IJ28, IJ31, IJ32, IJ33 586) IJ34, IJ35, IJ36, IJ39 587) IJ40, IJ41 Part of the The actuator and a wall of the ink 588) Significant reductions 590) Small increase in fabrication 591) IJ07, IJ20, IJ26, actuator moves chamber are arranged so that the in back-flow can be complexity IJ38 to shut off the motion of the actuator closes off the achieved inlet inlet. 589) Compact designs possible Nozzle actuator In some configurations of ink jet, 592) Ink back-flow problem 593) None related to ink back-flow on 594) Silverbrook, EP does not result there is no expansion or movement of is eliminated actuation 0771 658 A2 and in ink back-flow an actuator which may cause ink related patent back-flow through the inlet. applications 595) Valve-jet 596) Tone-jet 597) IJ08, IJ13, IJ15, IJ17 598) IJ18, IJ19, IJ21

[0180] Nozzle Clearing Method Nozzle Clearing method Description Advantages Disadvantages Examples Normal nozzle All of the nozzles are fired 599) No added complexity 600) May not be sufficient to displace 601) Most ink jet firing periodically, before the ink has a on the print head dried ink systems chance to dry. When not in use the 602) IJ01-IJ07, IJ09- nozzles are sealed (capped) against IJ12 air. 603) IJ14, IJ16, IJ20, The nozzle firing is usually IJ22 performed during a special clearing 604) IJ23-IJ34, IJ36- cycle, after first moving the print IJ45 head to a cleaning station. Extra power to In systems which heat the ink, but do 605) Can be highly 606) Requires higher drive voltage for 608) Silverbrook, EP ink heater not boil it under normal situations, effective if the heater is clearing 0771 658 A2 and nozzle clearing can be achieved by adjacent to the nozzle 607) May require larger drive related patent over-powering the heater and boiling transistors applications ink at the nozzle. Rapid The actuator is fired in rapid 609) Does not require extra 611) Effectiveness depends 612) May be used succession of succession. In some configurations, drive circuits on the print substantially upon the configuration of with: actuator pulses this may cause heat build-up at the head the inkjet nozzle 613) IJ01-IJ07, IJ09- nozzle which boils the ink, clearing 610) Can be readily IJ11 the nozzle. In other situations, it may controlled and initiated by 614) IJ14, IJ16, IJ20, cause sufficient vibrations to digital logic IJ22 dislodge clogged nozzles. 615) IJ23-IJ25, IJ27- IJ34 616) IJ36-IJ45 Extra power to Where an actuator is not normally 617) A simple solution 618) Not suitable where there is a hard 619) May be used ink pushing driven to the limit of its motion, where applicable limit to actuator movement with: actuator nozzle clearing may be assisted by 620) IJ03, IJ09, IJ16, providing an enhanced drive signal to IJ20 the actuator. 621) IJ23, IJ24, IJ25, IJ27 622) IJ29, IJ30, IJ31, IJ32 623) IJ39, IJ40, IJ41, IJ42 624) IJ43, IJ44, IJ45 Acoustic An ultrasonic wave is applied to the 625) A high nozzle clearing 627) High implementation cost if 628) IJ08, IJ13, IJ15, resonance ink chamber. This wave is of an capability can be achieved system does not already include an IJ17 appropriate amplitude and frequency 626) May be implemented acoustic actuator 629) IJ18, IJ19, IJ21 to cause sufficient force at the nozzle at very low cost in systems to clear blockages. This is easiest to which already include achieve if the ultrasonic wave is at a acoustic actuators resonant frequency of the ink cavity. Nozzle clearing A microfabricated plate is pushed 630) Can clear severely 631) Accurate mechanical alignment is 635) Silverbrook, EP plate against the nozzles. The plate has a clogged nozzles required 0771 658 A2 and post for every nozzle. The array of 632) Moving parts are required related patent posts 633) There is risk of damage to the applications nozzles 634) Accurate fabrication is required Ink pressure The pressure of the ink is temporarily 636) May be effective 637) Requires pressure pump or other 640) May be used pulse increased so that ink streams from all where other methods cannot pressure actuator with all IJ series ink of the nozzles. This may be used in be used 638) Expensive jets conjunction with actuator energizing. 639) Wasteful of ink Print head wiper A flexible ‘blade’ is wiped across the 641) Effective for planar 643) Difficult to use if print head 646) Many ink jet print head surface. The blade is print head surfaces surface is non-planar or very fragile systems usually fabricated from a flexible 642) Low cost 644) Requires mechanical parts polymer, e.g. rubber or synthetic 645) Blade can wear out in high elastomer. volume print systems Separate ink A separate heater is provided at the 647) Can be effective 649) Fabrication complexity 650) Can be used boiling heater nozzle although the normal drop e- where other nozzle clearing with many IJ series ection mechanism does not require it. methods cannot be used ink jets The heaters do not require individual 648) Can be implemented drive circuits, as many nozzles can at no additional cost in be cleared simultaneously, and no some inkjet configurations imaging is required.

[0181] Nozzle Plate Construction Nozzle plate construction Description Advantages Disadvantages Examples Electro- A nozzle plate is separately 651) Fabrication simplicity 652) High temperatures and pressures 655) Hewlett Packard formed fabricated from electroformed nickel, are required to bond nozzle plate Thermal Inkjet nickel and bonded to the print head 653) Minimum thickness constraints integrated circuit. 654) Differential thermal expansion Laser Individual nozzle holes are ablated 656) No masks required 660) Each hole must be individually 664) Canon ablated or by an intense UV laser in a nozzle 657) Can be quite fast formed Bubblejet drilled plate, which is typically a polymer 658) Some control over 661) Special equipment required 665) 1988 Sercel et al., polymer such as polyimide or polysulphone nozzle profile is possible 662) Slow where there are many SPIE, Vol. 998 659) Equipment required is thousands of nozzles per print head Excimer Beam relatively low cost 663) May produce thin burrs at exit Applications, pp. 76-83 holes 666) 1993 Watanabe et al., U.S. Pat. No. 5,208,604 Silicon A separate nozzle plate is 667) High accuracy is 668) Two part construction 672) K. Bean, IEEE micro- micromachined from single crystal attainable 669) High cost Transactions on machined silicon, and bonded to the print head 670) Requires precision alignment Electron Devices, wafer. 671) Nozzles may be clogged by Vol. ED-25, No. 10, adhesive 1978, pp 1185-1195 673) Xerox 1990 Hawkins et al., U.S. Pat. No. 4,899,181 Glass Fine glass capillaries are drawn from 674) No expensive 676) Very small nozzle sizes are 678) 1970 Zoltan capillaries glass tubing. This method has been equipment required difficult to form U.S. Pat. No. 3,683,212 used for making individual nozzles, 675) Simple to make single 677) Not suited for mass production but is difficult to use for bulk nozzles manufacturing of print heads with thousands of nozzles. Monolithic, The nozzle plate is deposited as a 679) High accuracy (<1 μm) 683) Requires sacrificial layer under 685) Silverbrook, EP surface layer using standard VLSI deposition 680) Monolithic the nozzle plate to form the nozzle 0771 658 A2 and micro- techniques. Nozzles are etched in the 681) Low cost chamber related patent machined nozzle plate using VLSI lithography 682) Existing processes can 684) Surface may be fragile to the applications using and etching. be used touch 686) IJ01, IJ02, IJ04, VLSI IJ11 lithographic 687) IJ12, IJ17, IJ18, processes IJ20 688) IJ22, IJ24, IJ27, IJ28 689) IJ29, IJ30, IJ31, IJ32 690) IJ33, IJ34, IJ36, IJ37 691) IJ38, IJ39, IJ40, IJ41 692) IJ42, IJ43, IJ44 Monolithic, The nozzle plate is a buried etch stop 693) High accuracy (<1 μm) 697) Requires long etch times 699) IJ03, IJ05, IJ06, etched in the wafer. Nozzle chambers are 694) Monolithic 698) Requires a support wafer IJ07 through etched in the front of the wafer, and 695) Low cost 700) IJ08, IJ09, IJ10, substrate the wafer is thinned from the back 696) No differential IJ13 side. Nozzles are then etched in the expansion 701) IJ14, IJ15, IJ16, etch stop layer. IJ19 702) IJ21, IJ23, IJ25, IJ26 No nozzle Various methods have been tried to 703) No nozzles to become 704) Difficult to control drop position 706) Ricoh 1995 plate eliminate the nozzles entirely, to clogged accurately Sekiya et al U.S. Pat. No. prevent nozzle clogging. These 705) Crosstalk problems 5,412,413 include thermal bubble mechanisms 707) 1993 and acoustic lens mechanisms Hadimioglu et al EUP 550,192 708) 1993 Elrod et al EUP 572,220 Trough Each drop ejector has a trough 709) Reduced 711) Drop firing direction is sensitive 712) IJ35 through which a paddle moves. There manufacturing complexity to wicking. is no nozzle plate. 710) Monolithic Nozzle slit The elimination of nozzle holes and 713) No nozzles to become 714) Difficult to control drop position 716) 1989 Saito et al instead of replacement by a slit encompassing clogged accurately U.S. Pat. No. 4,799,068 individual many actuator positions reduces 715) Crosstalk problems nozzles nozzle clogging, but increases crosstalk due to ink surface waves

[0182] Drop Ejection Direction Ejection direction Description Advantages Disadvantages Examples Edge Ink flow is along the surface of the 717) Simple construction 722) Nozzles limited to edge 725) Canon (‘edge integrated circuit, and ink drops are 718) No silicon etching 723) High resolution is difficult Bubblejet 1979 Endo shooter’) ejected from the integrated circuit required 724) Fast color printing requires one et al GB patent edge. 719) Good heat sinking via print head per color 2,007,162 substrate 726) Xerox heater-in- 720) Mechanically strong pit 1990 Hawkins et 721) Ease of integrated al U.S. Pat. No. 4,899,181 circuit handing 727) Tone-jet Surface Ink flow is along the surface of the 728) No bulk silicon 731) Maximum ink flow is severely 732) Hewlett- (‘roof shooter’) integrated circuit, and ink drops are etching required restricted Packard TIJ 1982 ejected from the integrated circuit 729) Silicon can make an Vaught et al U.S. Pat. No. surface, normal to the plane of the effective heat sink 4,490,728 integrated circuit. 730) Mechanical strength 733) IJ02, IJ11, IJ12, IJ20 734) IJ22 Through Ink flow is through the integrated 735) High ink flow 738) Requires bulk silicon etching 739) Silverbrook, EP integrated circuit, and ink drops are ejected 736) Suitable for pagewidth 0771 658 A2 and circuit, forward from the front surface of the print related patent (‘up shooter’) integrated circuit. 737) High nozzle packing applications density therefore low 740) IJ04, IJ17, IJ18, manufacturing cost IJ24 741) IJ27-IJ45 Through Ink flow is through the integrated 742) High ink flow 745) Requires wafer thinning 747) IJ01, IJ03, IJ05, integrated circuit, and ink drops are ejected 743) Suitable for pagewidth 746) Requires special handling during IJ06 circuit, reverse from the rear surface of the print manufacture 748) IJ07, IJ08, IJ09, (‘down integrated circuit. 744) High nozzle packing IJ10 shooter’) density therefore low 749) IJ13, IJ14, IJ15, manufacturing cost IJ16 750) IJ19, IJ21, IJ23, IJ25 751) IJ26 Through Ink flow is through the actuator, 752) Suitable for 753) Pagewidth print heads require 756) Epson Stylus actuator which is not fabricated as part of the piezoelectric print heads several thousand connections to drive 757) Tektronix hot same substrate as the drive circuits melt piezoelectric ink transistors. 754) Cannot be manufactured in jets standard CMOS fabs 755) Complex assembly required

[0183] Ink Type Ink type Description Advantages Disadvantages Examples Aqueous, dye Water based ink which typically 758) Environmentally 760) Slow drying 765) Most existing contains: water, dye, surfactant, friendly 761) Corrosive inkjets humectant, and biocide. 759) No odor 762) Bleeds on paper 766) All IJ series ink Modern ink dyes have high water- 763) May strikethrough jets fastness, light fastness 764) Cockles paper 767) Silverbrook, EP 0771 658 A2 and related patent applications Aqueous, Water based ink which typically 768) Environmentally 773) Slow drying 778) IJ02, IJ04, IJ21, pigment contains: water, pigment, surfactant, friendly 774) Corrosive IJ26 humectant, and biocide. 769) No odor 775) Pigment may clog nozzles 779) IJ27, IJ30 Pigments have an advantage in 770) Reduced bleed 776) Pigment may clog actuator 780) Silverbrook, EP reduced bleed, wicking and 771) Reduced wicking mechanisms 0771 658 A2 and strikethrough. 772) Reduced strikethrough 777) Cockles paper related patent applications 781) Piezoelectric ink-jets 782) Thermal ink jets (with significant restrictions) Methyl Ethyl MEK is a highly volatile solvent used 783) Very fast drying 785) Odorous 787) All IJ series ink Ketone (MEK) for industrial printing on difficult 784) Prints on various 786) Flammable jets surfaces such as aluminum cans. substrates such as metals and plastics Alcohol Alcohol based inks can be used 788) Fast drying 792) Slight odor 794) All IJ series ink (ethanol, 2- where the printer must operate at 789) Operates at sub- 793) Flammable jets butanol, and temperatures below the freezing freezing temperatures others) point of water. An example of this is 790) Reduced paper cockle in-camera consumer photographic 791) Low cost printing. Phase change The ink is solid at room temperature, 795) No drying time-ink 801) High viscosity 807) Tektronix hot (hot melt) and is melted in the print head before instantly freezes on the print 802) Printed ink typically has a ‘waxy’ melt piezoelectric ink jetting. Hot melt inks are usually wax medium feel jets based, with a melting point around 796) Almost any print 803) Printed pages may ‘block’ 808) 1989 Nowak U.S. 80° C. After jetting the ink freezes medium can be used 804) Ink temperature may be above the Pat. No. 4,820,346 almost instantly upon contacting the 797) No paper cockle curie point of permanent magnets 809) All IJ series ink print medium or a transfer roller. occurs 805) Ink heaters consume power jets 798) No wicking occurs 806) Long warm-up time 799) No bleed occurs 800) No strikethrough occurs Oil Oil based inks are extensively used in 810) High solubility 813) High viscosity: this is a 815) All IJ series ink offset printing. They have advantages medium for some dyes significant limitation for use in inkjets, jets in improved characteristics on paper 811) Does not cockle paper which usually require a low viscosity. (especially no wicking or cockle). Oil 812) Does not wick through Some short chain and multi-branched soluble dies and pigments are paper oils have a sufficiently low viscosity. required. 814) Slow drying Microemulsion A microemulsion is a stable, self 816) Stops ink bleed 820) Viscosity higher than water 823) All IJ series ink forming emulsion of oil, water, and 817) High dye solubility 821) Cost is slightly higher than water jets surfactant. The characteristic drop 818) Water, oil, and based ink size is less than 100 nm, and is amphiphilic soluble dies can 822) High surfactant concentration determined by the preferred be used required (around 5%) curvature of the surfactant. 819) Can stabilize pigment suspensions

[0184] Ink Jet Printing

[0185] A large number of new forms of ink jet printers have been developed to facilitate alternative ink jet technologies for the image processing and data distribution system. Various combinations of ink jet devices can be included in printer devices incorporated as part of the present invention. Australian Provisional Patent Applications relating to these ink jets which are specifically incorporated by cross reference. The serial numbers of respective corresponding US patent applications are also provided for the sake of convenience. Australian Provisional US Patent/Patent Application Number Filing Date Title and Filing Date PO8066 15-Jul-97 Image Creation Method and Apparatus (IJ01) 6,227,652 (Jul. 10, 1998) PO8072 15-Jul-97 Image Creation Method and Apparatus (IJ02) 6,213,588 (Jul. 10, 1998) PO8040 15-Jul-97 Image Creation Method and Apparatus (IJ03) 6,213,589 (Jul. 10, 1998) PO8071 15-Jul-97 Image Creation Method and Apparatus (IJ04) 6,231,163 (Jul. 10, 1998) PO8047 15-Jul-97 Image Creation Method and Apparatus (IJ05) 6,247,795 (Jul. 10, 1998) PO8035 15-Jul-97 Image Creation Method and Apparatus (IJ06) 6,394,581 (Jul. 10, 1998) PO8044 15-Jul-97 Image Creation Method and Apparatus (IJ07) 6,244,691 (Jul. 10, 1998) PO8063 15-Jul-97 Image Creation Method and Apparatus (IJ08) 6,257,704 (Jul. 10, 1998) PO8057 15-Jul-97 Image Creation Method and Apparatus (IJ09) 6,416,168 (Jul. 10, 1998) PO8056 15-Jul-97 Image Creation Method and Apparatus (IJ10) 6,220,694 (Jul. 10, 1998) PO8069 15-Jul-97 Image Creation Method and Apparatus (IJ11) 6,257,705 (Jul. 10, 1998) PO8049 15-Jul-97 Image Creation Method and Apparatus (IJ12) 6,247,794 (Jul. 10, 1998) PO8036 15-Jul-97 Image Creation Method and Apparatus (IJ13) 6,234,610 (Jul. 10, 1998) PO8048 15-Jul-97 Image Creation Method and Apparatus (IJ14) 6,247,793 (Jul. 10, 1998) PO8070 15-Jul-97 Image Creation Method and Apparatus (IJ15) 6,264,306 (Jul. 10, 1998) PO8067 15-Jul-97 Image Creation Method and Apparatus (IJ16) 6,241,342 (Jul. 10, 1998) PO8001 15-Jul-97 Image Creation Method and Apparatus (IJ17) 6,247,792 (Jul. 10, 1998) PO8038 15-Jul-97 Image Creation Method and Apparatus (IJ18) 6,264,307 (Jul. 10, 1998) PO8033 15-Jul-97 Image Creation Method and Apparatus (IJ19) 6,254,220 (Jul. 10, 1998) PO8002 15-Jul-97 Image Creation Method and Apparatus (IJ20) 6,234,611 (Jul. 10, 1998) PO8068 15-Jul-97 Image Creation Method and Apparatus (IJ21) 6,302,528) (Jul. 10, 1998) PO8062 15-Jul-97 Image Creation Method and Apparatus (IJ22) 6,283,582 (Jul. 10, 1998) PO8034 15-Jul-97 Image Creation Method and Apparatus (IJ23) 6,239,821 (Jul. 10, 1998) PO8039 15-Jul-97 Image Creation Method and Apparatus (IJ24) 6,338,547 (Jul. 10, 1998) PO8041 15-Jul-97 Image Creation Method and Apparatus (IJ25) 6,247,796 (Jul. 10, 1998) PO8004 15-Jul-97 Image Creation Method and Apparatus (IJ26) 09/113,122 (Jul. 10, 1998) PO8037 15-Jul-97 Image Creation Method and Apparatus (IJ27) 6,390,603 (Jul. 10, 1998) PO8043 15-Jul-97 Image Creation Method and Apparatus (IJ28) 6,362,843 (Jul. 10, 1998) PO8042 15-Jul-97 Image Creation Method and Apparatus (IJ29) 6,293,653 (Jul. 10, 1998) PO8064 15-Jul-97 Image Creation Method and Apparatus (IJ30) 6,312,107 (Jul. 10, 1998) PO9389 23-Sep-97 Image Creation Method and Apparatus (IJ31) 6,227,653 (Jul. 10, 1998) PO9391 23-Sep-97 Image Creation Method and Apparatus (IJ32) 6,234,609 (Jul. 10, 1998) PP0888 12-Dec-97 Image Creation Method and Apparatus (IJ33) 6,238,040 (Jul. 10, 1998) PP0891 12-Dec-97 Image Creation Method and Apparatus (IJ34) 6,188,415 (Jul. 10, 1998) PP0890 12-Dec-97 Image Creation Method and Apparatus (IJ35) 6,227,654 (Jul. 10, 1998) PP0873 12-Dec-97 Image Creation Method and Apparatus (IJ36) 6,209,989 (Jul. 10, 1998) PP0993 12-Dec-97 Image Creation Method and Apparatus (IJ37) 6,247,791 (Jul. 10, 1998) PP0890 12-Dec-97 Image Creation Method and Apparatus (IJ38) 6,336,710 (Jul. 10, 1998) PP1398 19-Jan-98 An Image Creation Method and Apparatus 6,217,153 (IJ39) (Jul. 10, 1998) PP2592 25-Mar-98 An Image Creation Method and Apparatus 6,416,167 (IJ40) (Jul. 10, 1998) PP2593 25-Mar-98 Image Creation Method and Apparatus (IJ41) 6,243,113 (Jul. 10, 1998) PP3991 9-Jun-98 Image Creation Method and Apparatus (IJ42) 6,283,581 (Jul. 10, 1998) PP3987 9-Jun-98 Image Creation Method and Apparatus (IJ43) 6,247,790 (Jul. 10, 1998) PP3985 9-Jun-98 Image Creation Method and Apparatus (IJ44) 6,260,953 (Jul. 10, 1998) PP3983 9-Jun-98 Image Creation Method and Apparatus (IJ45) 6,267,469 (Jul. 10, 1998)

[0186] Ink Jet Manufacturing

[0187] Further, the present application may utilize advanced semiconductor fabrication techniques in the construction of large arrays of ink jet printers. Suitable manufacturing techniques are described in the following Australian provisional patent specifications incorporated here by cross-reference. The serial numbers of respective corresponding US patent applications are also provided for the sake of convenience. Australian Provisional US Patent/Patent Application Number Filing Date Title and Filing Date PO7935 15-Jul-97 A Method of Manufacture of an Image Creation 6,224,780 Apparatus (IJM01) (Jul. 10, 1998) PO7936 15-Jul-97 A Method of Manufacture of an Image Creation 6,235,212 Apparatus (IJM02) (Jul. 10, 1998) PO7937 15-Jul-97 A Method of Manufacture of an Image Creation 6,280,643 Apparatus (IJM03) (Jul. 10, 1998) PO8061 15-Jul-97 A Method of Manufacture of an Image Creation 6,284,147 Apparatus (IJM04) (Jul. 10, 1998) PO8054 15-Jul-97 A Method of Manufacture of an Image Creation 6,214,244 Apparatus (IJM05) (Jul. 10, 1998) PO8065 15-Jul-97 A Method of Manufacture of an Image Creation 6,071,750 Apparatus (IJM06) (Jul. 10, 1998) PO8055 15-Jul-97 A Method of Manufacture of an Image Creation 6,267,905 Apparatus (IJM07) (Jul. 10, 1998) PO8053 15-Jul-97 A Method of Manufacture of an Image Creation 6,251,298 Apparatus (IJM08) (Jul. 10, 1998) PO8078 15-Jul-97 A Method of Manufacture of an Image Creation 6,258,285 Apparatus (IJM09) (Jul. 10, 1998) PO7933 15-Jul-97 A Method of Manufacture of an Image Creation 6,225,138 Apparatus (IJM10) (Jul. 10, 1998) PO7950 15-Jul-97 A Method of Manufacture of an Image Creation 6,241,904 Apparatus (IJM11) (Jul. 10, 1998) PO7949 15-Jul-97 A Method of Manufacture of an Image Creation 6,299,786 Apparatus (IJM12) (Jul. 10, 1998) PO8060 15-Jul-97 A Method of Manufacture of an Image Creation 09/113,124 Apparatus (IJM13) (Jul. 10, 1998) PO8059 15-Jul-97 A Method of Manufacture of an Image Creation 6,231,773 Apparatus (IJM14) (Jul. 10, 1998) PO8073 15-Jul-97 A Method of Manufacture of an Image Creation 6,190,931 Apparatus (IJM15) (Jul. 10, 1998) PO8076 15-Jul-97 A Method of Manufacture of an Image Creation 6,248,249 Apparatus (IJM16) (Jul. 10, 1998) PO8075 15-Jul-97 A Method of Manufacture of an Image Creation 6,290,862 Apparatus (IJM17) (Jul. 10, 1998) PO8079 15-Jul-97 A Method of Manufacture of an Image Creation 6,241,906 Apparatus (IJM18) (Jul. 10, 1998) PO8050 15-Jul-97 A Method of Manufacture of an Image Creation 09/113,116 Apparatus (IJM19) (Jul. 10, 1998) PO8052 15-Jul-97 A Method of Manufacture of an Image Creation 6,241,905 Apparatus (IJM20) (Jul. 10, 1998) PO7948 15-Jul-97 A Method of Manufacture of an Image Creation 6,451,216 Apparatus (IJM21) (Jul. 10, 1998) PO7951 15-Jul-97 A Method of Manufacture of an Image Creation 6,231,772 Apparatus (IJM22) (Jul. 10, 1998) PO8074 15-Jul-97 A Method of Manufacture of an Image Creation 6,274,056 Apparatus (IJM23) (Jul. 10, 1998) PO7941 15-Jul-97 A Method of Manufacture of an Image Creation 6,290,861 Apparatus (IJM24) (Jul. 10, 1998) PO8077 15-Jul-97 A Method of Manufacture of an Image Creation 6,248,248 Apparatus (IJM25) (Jul. 10, 1998) PO8058 15-Jul-97 A Method of Manufacture of an Image Creation 6,306,671 Apparatus (IJM26) (Jul. 10, 1998) PO8051 15-Jul-97 A Method of Manufacture of an Image Creation 6,331,258 Apparatus (IJM27) (Jul. 10, 1998) PO8045 15-Jul-97 A Method of Manufacture of an Image Creation 6,110,754 Apparatus (IJM28) (Jul. 10, 1998) PO7952 15-Jul-97 A Method of Manufacture of an Image Creation 6,294,101 Apparatus (IJM29) (Jul. 10, 1998) PO8046 15-Jul-97 A Method of Manufacture of an Image Creation 6,416,679 Apparatus (IJM30) (Jul. 10, 1998) PO8503 11-Aug-97 A Method of Manufacture of an Image Creation 6,264,849 Apparatus (IJM30a) (Jul. 10, 1998) PO9390 23-Sep-97 A Method of Manufacture of an Image Creation 6,254,793 Apparatus (IJM31) (Jul. 10, 1998) PO9392 23-Sep-97 A Method of Manufacture of an Image Creation 6,235,211 Apparatus (IJM32) (Jul. 10, 1998) PP0889 12-Dec-97 A Method of Manufacture of an Image Creation 6,235,211 Apparatus (IJM35) (Jul. 10, 1998) PP0887 12-Dec-97 A Method of Manufacture of an Image Creation 6,264,850 Apparatus (IJM36) (Jul. 10, 1998) PP0882 12-Dec-97 A Method of Manufacture of an Image Creation 6,258,284 Apparatus (IJM37) (Jul. 10, 1998) PP0874 12-Dec-97 A Method of Manufacture of an Image Creation 6,258,284 Apparatus (IJM38) (Jul. 10, 1998) PP1396 19-Jan-98 A Method of Manufacture of an Image Creation 6,228,668 Apparatus (IJM39) (Jul. 10, 1998) PP2591 25-Mar-98 A Method of Manufacture of an Image Creation 6,180,427 Apparatus (IJM41) (Jul. 10, 1998) PP3989 9-Jun-98 A Method of Manufacture of an Image Creation 6,171,875 Apparatus (IJM40) (Jul. 10, 1998) PP3990 9-Jun-98 A Method of Manufacture of an Image Creation 6,267,904 Apparatus (IJM42) (Jul. 10, 1998) PP3986 9-Jun-98 A Method of Manufacture of an Image Creation 6,245,247 Apparatus (IJM43) (Jul. 10, 1998) PP3984 9-Jun-98 A Method of Manufacture of an Image Creation 6,245,247 Apparatus (IJM44) (Jul. 10, 1998) Apparatus (IJM44) PP3982 9-Jun-98 A Method of Manufacture of an Image Creation 6,231,148 Apparatus (IJM45) (Jul. 10, 1998)

[0188] Fluid Supply

[0189] Further, the present application may utilize an ink delivery system to the ink jet head. Delivery systems relating to the supply of ink to a series of ink jet nozzles are described in the following Australian provisional patent specifications, the disclosure of which are hereby incorporated by cross-reference. The serial numbers of respective corresponding US patent applications are also provided for the sake of convenience. Australian US Patent/Patent Provisional Application and Number Filing Date Title Filing Date PO8003 15-Jul-97 Supply Method and 6,350,023 Apparatus (F1) (Jul. 10, 1998) PO8005 15-Jul-97 Supply Method and 6,318,849 Apparatus (F2) (Jul. 10, 1998) PO9404 23-Sep-97 A Device and 09/113,101 Method (F3) (Jul. 10, 1998)

[0190] MEMS Technology

[0191] Further, the present application may utilize advanced semiconductor microelectromechanical techniques in the construction of large arrays of ink jet printers. Suitable microelectromechanical techniques are described in the following Australian provisional patent specifications incorporated here by cross-reference. The serial numbers of respective corresponding US patent applications are also provided for the sake of convenience. Australian US Patent/Patent Provisional Application and Number Filing Date Title Filing Date PO7943 15-Jul-97 A device (MEMS01) PO8006 15-Jul-97 A device (MEMS02) 6,087,638 (Jul. 10, 1998) PO8007 15-Jul-97 A device (MEMS03) 09/113,093 (Jul. 10, 1998) PO8008 15-Jul-97 A device (MEMS04) 6,340,222 (Jul. 10, 1998) PO8010 15-Jul-97 A device (MEMS05) 6,041,600 (Jul. 10, 1998) PO8011 15-Jul-97 A device (MEMS06) 6,299,300 (Jul. 10, 1998) PO7947 15-Jul-97 A device (MEMS07) 6,067,797 (Jul. 10, 1998) PO7945 15-Jul-97 A device (MEMS08) 09/113,081 (Jul. 10, 1998) PO7944 15-Jul-97 A device (MEMS09) 6,286,935 (Jul. 10, 1998) PO7946 15-Jul-97 A device (MEMS10) 6,044,646 (Jul. 10, 1998) PO9393 23-Sep-97 A Device and 09/113,065 Method (MEMS11) (Jul. 10, 1998) PP0875 12-Dec-97 A Device (MEMS12) 09/113,078 (Jul. 10, 1998) PP0894 12-Dec-97 A Device and 09/113,075 Method (MEMS13) (Jul. 10, 1998)

[0192] IR Technologies

[0193] Further, the present application may include the utilization of a disposable camera system such as those described in the following Australian provisional patent specifications incorporated here by cross-reference. The serial numbers of respective corresponding US patent applications are also provided for the sake of convenience. Australian Provisional US Patent/Patent Application and Number Filing Date Title Filing Date PP0895 12-Dec-97 An Image Creation Method and Apparatus 6,231,148 (IR01) (Jul. 10, 1998) PP0870 12-Dec-97 A Device and Method (IR02) 09/113,106 (Jul. 10, 1998) PP0869 12-Dec-97 A Device and Method (IR04) 6,293,658 (Jul. 10, 1998) PP0887 12-Dec-97 Image Creation Method and Apparatus 09/113,104 (IR05) (Jul. 10, 1998) PP0885 12-Dec-97 An Image Production System (IR06) 6,238,033 (Jul. 10, 1998) PP0884 12-Dec-97 Image Creation Method and Apparatus 6,312,070 (IR10) (Jul. 10, 1998) PP0886 12-Dec-97 Image Creation Method and Apparatus 6,238,111 (IR12) (Jul. 10, 1998) PP0871 12-Dec-97 A Device and Method (IR13) 09/113,086 (Jul. 10, 1998) PP0876 12-Dec-97 An Image Processing Method and Apparatus 09/113,094 (IR14) (Jul. 10, 1998) PP0877 12-Dec-97 A Device and Method (IR16) 6,378,970 (Jul. 10, 1998) PP0878 12-Dec-97 A Device and Method (IR17) 6,196,739 (Jul. 10, 1998) PP0879 12-Dec-97 A Device and Method (IR18) 09/112,774 (Jul. 10, 1998) PP0883 12-Dec-97 A Device and Method (IR19) 6,270,182 (Jul. 10, 1998) PP0880 12-Dec-97 A Device and Method (IR20) 6,152,619 (Jul. 10, 1998) PP0881 12-Dec-97 A Device and Method (IR21) 09/113,092 (Jul. 10, 1998)

[0194] DotCard Technologies

[0195] Further, the present application may include the utilization of a data distribution system such as that described in the following Australian provisional patent specifications incorporated here by cross-reference. The serial numbers of respective corresponding US patent applications are also provided for the sake of convenience. Australian US Patent/Patent Provisional Application and Number Filing Date Title Filing Date PP2370 16-Mar-98 Data Processing 09/112,781 Method and (Jul. 10, 1998) Apparatus (Dot01) PP2371 16-Mar-98 Data Processing 09/113,052 Method and (Jul. 10, 1998 Apparatus (Dot02)

[0196] Artcam Technologies

[0197] Further, the present application may include the utilization of camera and data processing techniques such as an Artcam type device as described in the following Australian provisional patent specifications incorporated here by cross-reference. The serial numbers of respective corresponding US patent applications are also provided for the sake of convenience. Australian Provisional US Patent/Patent Application and Number Filing Date Title Filing Date PO7991 15-Jul-97 Image Processing Method and Apparatus 09/113,060 (ART01) (Jul. 10, 1998) PO7988 15-Jul-97 Image Processing Method and Apparatus 6,476,863 (ART02) (Jul. 10, 1998) PO7993 15-Jul-97 Image Processing Method and Apparatus 09/113,073 (ART03) (Jul. 10, 1998) PO9395 23-Sep-97 Data Processing Method and Apparatus 6,322,181 (ART04) (Jul. 10, 1998) PO8017 15-Jul-97 Image Processing Method and Apparatus 09/112,747 (ART06) (Jul. 10, 1998) PO8014 15-Jul-97 Media Device (ART07) 6,227,648 (Jul. 10, 1998) PO8025 15-Jul-97 Image Processing Method and Apparatus 09/112,750 (ART08) (Jul. 10, 1998) PO8032 15-Jul-97 Image Processing Method and Apparatus 09/112,746 (ART09) (Jul. 10, 1998) PO7999 15-Jul-97 Image Processing Method and Apparatus 09/112,743 (ART10) (Jul. 10, 1998) PO7998 15-Jul-97 Image Processing Method and Apparatus 09/112,742 (ART11) (Jul. 10, 1998) PO8031 15-Jul-97 Image Processing Method and Apparatus 09/112,741 (ART12) (Jul. 10, 1998) PO8030 15-Jul-97 Media Device (ART13) 6,196,541 (Jul. 10, 1998) PO7997 15-Jul-97 Media Device (ART15) 6,195,150 (Jul. 10, 1998) PO7979 15-Jul-97 Media Device (ART16) 6,362,868 (Jul. 10, 1998) PO8015 15-Jul-97 Media Device (ART17) 09/112,738 (Jul. 10, 1998) PO7978 15-Jul-97 Media Device (ART18) 09/113,067 (Jul. 10, 1998) PO7982 15-Jul-97 Data Processing Method and Apparatus 6,431,669 (ART19) (Jul. 10, 1998 PO7989 15-Jul-97 Data Processing Method and Apparatus 6,362,869 (ART20) (Jul. 10, 1998 PO8019 15-Jul-97 Media Processing Method and Apparatus 6,472,052 (ART21) (Jul. 10, 1998 PO7980 15-Jul-97 Image Processing Method and Apparatus 6,356,715 (ART22) (Jul. 10, 1998) PO8018 15-Jul-97 Image Processing Method and Apparatus 09/112,777 (ART24) (Jul. 10, 1998) PO7938 15-Jul-97 Image Processing Method and Apparatus 09/113,224 (ART25) (Jul. 10, 1998) PO8016 15-Jul-97 Image Processing Method and Apparatus 6,366,693 (ART26) (Jul. 10, 1998) PO8024 15-Jul-97 Image Processing Method and Apparatus 6,329,990 (ART27) (Jul. 10, 1998) PO7940 15-Jul-97 Data Processing Method and Apparatus 09/113,072 (ART28) (Jul. 10, 1998) PO7939 15-Jul-97 Data Processing Method and Apparatus 09/112,785 (ART29) (Jul. 10, 1998) PO8501 11-Aug-97 Image Processing Method and Apparatus 6,137,500 (ART30) (Jul. 10, 1998) PO8500 11-Aug-97 Image Processing Method and Apparatus 09/112,796 (ART31) (Jul. 10, 1998) PO7987 15-Jul-97 Data Processing Method and Apparatus 09/113,071 (ART32) (Jul. 10, 1998) PO8022 15-Jul-97 Image Processing Method and Apparatus 6,398,328 (ART33) (Jul. 10, 1998 PO8497 11-Aug-97 Image Processing Method and Apparatus 09/113,090 (ART34) (Jul. 10, 1998) PO8020 15-Jul-97 Data Processing Method and Apparatus 6,431,704 (ART38) (Jul. 10, 1998 PO8023 15-Jul-97 Data Processing Method and Apparatus 09/113,222 (ART39) (Jul. 10, 1998) PO8504 11-Aug-97 Image Processing Method and Apparatus 09/112,786 (ART42) (Jul. 10, 1998) PO8000 15-Jul-97 Data Processing Method and Apparatus 6,415,054 (ART43) (Jul. 10, 1998) PO7977 15-Jul-97 Data Processing Method and Apparatus 09/112,782 (ART44) (Jul. 10, 1998) PO7934 15-Jul-97 Data Processing Method and Apparatus 09/113,056 (ART45) (Jul. 10, 1998) PO7990 15-Jul-97 Data Processing Method and Apparatus 09/113,059 (ART46) (Jul. 10, 1998) PO8499 11-Aug-97 Image Processing Method and Apparatus 6,486,886 (ART47) (Jul. 10, 1998) PO8502 11-Aug-97 Image Processing Method and Apparatus 6,381,361 (ART48) (Jul. 10, 1998) PO7981 15-Jul-97 Data Processing Method and Apparatus 6,317,192 (ART50) (Jul. 10, 1998 PO7986 15-Jul-97 Data Processing Method and Apparatus 09/113,057 (ART51) (Jul. 10, 1998) PO7983 15-Jul-97 Data Processing Method and Apparatus 09/113,054 (ART52) (Jul. 10, 1998) PO8026 15-Jul-97 Image Processing Method and Apparatus 09/112,752 (ART53) (Jul 10, 1998) PO8027 15-Jul-97 Image Processing Method and Apparatus 09/112,759 (ART54) (Jul. 10, 1998) PO8028 15-Jul-97 Image Processing Method and Apparatus 09/112,757 (ART56) (Jul. 10, 1998) PO9394 23-Sep-97 Image Processing Method and Apparatus 6,357,135 (ART57) (Jul. 10, 1998 PO9396 23-Sep-97 Data Processing Method and Apparatus 09/113,107 (ART58) (Jul. 10, 1998) PO9397 23-Sep-97 Data Processing Method and Apparatus 6,271,931 (ART59) (Jul. 10, 1998) PO9398 23-Sep-97 Data Processing Method and Apparatus 6,353,772 (ART60) (Jul. 10, 1998) PO9399 23-Sep-97 Data Processing Method and Apparatus 6,106,147 (ART61) (Jul. 10, 1998) PO9400 23-Sep-97 Data Processing Method and Apparatus 09/112,790 (ART62) (Jul. 10, 1998) PO9401 23-Sep-97 Data Processing Method and Apparatus 6,304,291 (ART63) (Jul. 10, 1998) PO9402 23-Sep-97 Data Processing Method and Apparatus 09/112,788 (ART64) (Jul. 10, 1998) PO9403 23-Sep-97 Data Processing Method and Apparatus 6,305,770 (ART65) (Jul. 10, 1998) PO9405 23-Sep-97 Data Processing Method and Apparatus 6,289,262 (ART66) (Jul. 10, 1998) PP0959 16-Dec-97 A Data Processing Method and Apparatus 6,315,200 (ART68) (Jul. 10, 1998) PP1397 19-Jan-98 A Media Device (ART69) 6,217,165 (Jul. 10, 1998) 

We claim:
 1. A printhead assembly for a camera system having a chassis and a platen assembly that is mountable on the chassis, the platen assembly being configured to support passage of a print medium along a printing path, the printhead assembly comprising an ink reservoir assembly that is mountable on the chassis and defines at least three ink reservoirs in which respective differently colored inks are received, the ink reservoir assembly defining an outlet; a guide assembly that is positioned in the ink reservoir assembly to define at least three discrete ink paths that open at the outlet; and at least one printhead integrated circuit that is positioned in the outlet to span the printing path, the, or each, printhead integrated circuit defining at least three sets of inlet apertures, each set of inlet apertures being aligned with a respective ink path.
 2. A printhead assembly as claimed in claim 1, in which the ink reservoir assembly defines three ink reservoirs and the guide assembly defines three discrete ink paths.
 3. A printhead assembly as claimed in claim 2, in which both the ink reservoir assembly and the guide assembly are elongate to span the printing path, the ink reservoir assembly including an elongate base member and an elongate cover member, the cover member having a roof wall, a pair of opposed side walls and a pair of spaced inner walls, the side walls and the inner walls depending from the roof wall and being generally parallel to each other and the base member having a floor and a pair of opposed end walls and defining an elongate opening in which the printhead integrated circuits are mounted, the guide assembly being interposed between lower ends of the inner walls and the floor.
 4. A printhead assembly as claimed in claim 3, in which the guide assembly includes a pair of guide walls that extend from respective lower ends of the inner walls inwardly towards the elongate opening to define the three distinct ink paths that terminate at respective sets of inlet apertures of the printhead integrated circuits.
 5. A printhead assembly as claimed in claim 3, in which the base member, the cover member and the guide assembly are molded of a plastics material.
 6. A printhead assembly as claimed in claim 3, in which one of the end walls defines a number of air inlet openings that are treated to be hydrophobic to permit the ingress of air into the ink reservoirs as ink is fed from the ink reservoirs and to inhibit the egress of ink.
 7. A printhead assembly as claimed in claim 1, in which a sponge-like member is positioned in each ink reservoir to store the ink while inhibiting agitation of ink during general use of the camera system.
 8. A camera system that includes a printhead assembly as claimed in claim
 1. 